Found 35 papers in cond-mat
Date of feed: Wed, 15 Nov 2023 01:30:00 GMT

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Chiral Symmetry Restoration and the Ultraquantum limit of Axionic Charge Density Waves in Weyl Semimetals. (arXiv:2311.07644v1 [cond-mat.str-el])
Joan Bernabeu, Alberto Cortijo

A new mechanism for chiral symmetry restoration at extreme high magnetic fields is proposed in the context of the Magnetic Catalysis scenario in Weyl Semimetals. Contrary to previous proposals, here we show that, at very large magnetic fields, the transverse velocity of the axion field, the phase mode of the chiral condensate $\langle\bar{\psi}\psi\rangle$, becomes effectively one-dimensional and its fluctuations destroy a possible nonzero value of this fermionic condensate. We also show that, despite of the $U(1)$ chiral symmetry is not broken at extremely large magnetic fields, the spectrum of the system is comprised by a well defined gapless bosonic excitation, connected to the axion mode, and a correlated insulating fermionic liquid that is neutral to $U(1)$ chiral transformations. We also discuss some consequences of this theory that can be contrasted to experiments.


Polyurea-Graphene Nanocomposites -- the Influence of Hard-Segment Content and Nanoparticle Loading on Mechanical Properties. (arXiv:2311.07721v1 [cond-mat.mtrl-sci])
Demetrios A. Tzelepis, Arman Khoshnevis, Mohsen Zayernouri, Valeriy V. Ginzburg

Polyurethane and polyurea-based adhesives are widely used in various applications, from automotive to electronics to medical. The adhesive performance depends strongly on its composition, and developing the formulation-structure-property relationship is crucial to making better products. Here, we investigate the dependence of the linear viscoelastic properties of polyurea nanocomposites, with IPDI-based polyurea (PUa) matrix and exfoliated graphene nanoplatelet (xGnP) fillers, on the hard segment weight fraction (HSWF) and the xGnP loading. We characterize the material using scanning electron microscopy (SEM) and dynamical mechanical analysis (DMA). It is found that changing HSWF leads to a significant variation in the stiffness of the material, from about 10 MPa for the 20% HSWF to about 100 MPa for the 30% HSWF to about 250 MPa for the 40% HSWF polymer (as measured by the tensile storage modulus at room temperature). The effect of the xGNP loading is significantly more limited and is generally within experimental error, except for the 20% HSWF material where the xGNP addition leads to about 80% increase in stiffness. To correctly interpret the DMA results, we developed a new physics-based rheological model for the description of the storage and loss moduli. The model is based on the fractional calculus approach and successfully describes the material rheology in a broad range of temperatures (-70{\deg}C to +70{\deg}C) and frequencies (0.1 to 100 s-1), using only six physically meaningful fitting parameters for each material. The results provide guidance for the development of nanocomposite PUa-based materials.


Ab initio amorphous spin Hamiltonian for the description of topological spin textures in FeGe. (arXiv:2311.07725v1 [cond-mat.mtrl-sci])
Temuujin Bayaraa, Sinéad M. Griffin

Topological spin textures in magnetic materials such as skyrmions and hopfions are interesting manifestations of geometric structures in real materials, concurrently having potential applications as information carriers. In the crystalline systems, the formation of these topological spin textures is well understood as a result of the competition between interactions due to symmetry breaking and frustration. However, in systems without translation symmetry such as amorphous materials, a fundamental understanding of the driving mechanisms of non-trivial spin structures is lacking owing to the structural and interaction complexity in these systems. In this work, we use a suite of first-principles-based calculations to propose an ab initio spin Hamiltonian that accurately represents the diversity of structural and magnetic properties in the exemplar amorphous FeGe. Monte Carlo simulations of our amorphous Hamiltonian find emergent skyrmions that are driven by frustrated geometric and magnetic exchange, consistent with those observed in experiment. Moreover, we find that the diversity of local structural motifs results in a large range of exchange interactions, far beyond those found in crystalline materials. Finally, we observe the formation of large-scale emergent structures in amorphous materials, far beyond the relevant interaction length-scale in the systems, suggesting a new route to emergent correlated phases beyond the crystalline limit.


Magnetic-coupled electronic landscape in bilayer-distorted titanium-based kagome metals. (arXiv:2311.07747v1 [cond-mat.mtrl-sci])
Yong Hu, Congcong Le, Long Chen, Hanbin Deng, Ying Zhou, Nicholas C. Plumb, Milan Radovic, Ronny Thomale, Andreas P. Schnyder, Jia-Xin Yin, Gang Wang, Xianxin Wu, Ming Shi

Quantum materials whose atoms are arranged on a lattice of corner-sharing triangles, $\textit{i.e.}$, the kagome lattice, have recently emerged as a captivating platform for investigating exotic correlated and topological electronic phenomena. Here, we combine ultra-low temperature angle-resolved photoemission spectroscopy (ARPES) with scanning tunneling microscopy and density functional theory calculations to reveal the fascinating electronic structure of the bilayer-distorted kagome material $\textit{Ln}$Ti${_3}$Bi${_4}$, where $\textit{Ln}$ stands for Nd and Yb. Distinct from other kagome materials, $\textit{Ln}$Ti${_3}$Bi${_4}$ exhibits two-fold, rather than six-fold, symmetries, stemming from the distorted kagome lattice, which leads to a unique electronic structure. Combining experiment and theory we map out the electronic structure and discover double flat bands as well as multiple van Hove singularities (VHSs), with one VHS exhibiting higher-order characteristics near the Fermi level. Notably, in the magnetic version NdTi${_3}$Bi${_4}$, the ultra-low base temperature ARPES measurements unveil an unconventional band splitting in the band dispersions which is induced by the ferromagnetic ordering. These findings reveal the potential of bilayer-distorted kagome metals $\textit{Ln}$Ti${_3}$Bi${_4}$ as a promising platform for exploring novel emergent phases of matter at the intersection of strong correlation and magnetism.


Hybrid Synaptic Structure for Spiking Neural Network Realization. (arXiv:2311.07787v1 [cond-mat.supr-con])
Sasan Razmkhah, Mustafa Altay Karamuftuoglu, Ali Bozbey

Neural networks and neuromorphic computing play pivotal roles in deep learning and machine vision. Due to their dissipative nature and inherent limitations, traditional semiconductor-based circuits face challenges in realizing ultra-fast and low-power neural networks. However, the spiking behavior characteristic of single flux quantum (SFQ) circuits positions them as promising candidates for spiking neural networks (SNNs). Our previous work showcased a JJ-Soma design capable of operating at tens of gigahertz while consuming only a fraction of the power compared to traditional circuits, as documented in [1]. This paper introduces a compact SFQ-based synapse design that applies positive and negative weighted inputs to the JJ-Soma. Using an RSFQ synapse empowers us to replicate the functionality of a biological neuron, a crucial step in realizing a complete SNN. The JJ-Synapse can operate at ultra-high frequencies, exhibits orders of magnitude lower power consumption than CMOS counterparts, and can be conveniently fabricated using commercial Nb processes. Furthermore, the network's flexibility enables modifications by incorporating cryo-CMOS circuits for weight value adjustments. In our endeavor, we have successfully designed, fabricated, and partially tested the JJ-Synapse within our cryocooler system. Integration with the JJ-Soma further facilitates the realization of a high-speed inference SNN.


Imaging Self-aligned Moir\'e Crystals and Quasicrystals in Magic-angle Bilayer Graphene on hBN Heterostructures. (arXiv:2311.07819v1 [cond-mat.mes-hall])
Xinyuan Lai, Daniele Guerci, Guohong Li, Kenji Watanabe, Takashi Taniguchi, Justin Wilson, Jedediah H. Pixley, Eva Y. Andrei

Using scanning-tunneling-microscopy and theoretical modeling on heterostructures of twisted bilayer graphene and hexagonal Boron-Nitride, we show that the emergent super-moire structures display a rich landscape of moire-crystals and quasicrystals. We reveal a phase-diagram comprised of commensurate moire-crystals embedded in swaths of moire quasicrystals. The 1:1 commensurate crystal, expected to be a Chern insulator, should only exist at one point on the phase-diagram, implying that it ought to be practically undetectable. Surprisingly we find that the commensurate crystals exist over a much wider than predicted range, providing evidence of an unexpected self-alignment mechanism that is explained using an elastic-network model. The remainder of the phase-diagram, where we observe tunable quasicrystals, affords a new platform for exploring the unique electronic-properties of these rarely found in nature structures.


Topological and spectral properties of random digraphs. (arXiv:2311.07854v1 [cond-mat.dis-nn])
C. T. Martínez-Martínez, J. A. Méndez-Bermúdez, José M. Sigarreta

We investigate some topological and spectral properties of Erd\H{o}s-R\'{e}nyi (ER) random digraphs $D(n,p)$. In terms of topological properties, our primary focus lies in analyzing the number of non-isolated vertices $V_x(D)$ as well as two vertex-degree-based topological indices: the Randi\'c index $R(D)$ and sum-connectivity index $\chi(D)$. First, by performing a scaling analysis we show that the average degree $\langle k \rangle$ serves as scaling parameter for the average values of $V_x(D)$, $R(D)$ and $\chi(D)$. Then, we also state expressions relating the number of arcs, spectral radius, and closed walks of length 2 to $(n,p)$, the parameters of ER random digraphs. Concerning spectral properties, we compute six different graph energies on $D(n,p)$. We start by validating $\langle k \rangle$ as the scaling parameter of the graph energies. Additionally, we reformulate a set of bounds previously reported in the literature for these energies as a function $(n,p)$. Finally, we phenomenologically state relations between energies that allow us to extend previously known bounds.


Non-Hermitian topological wall modes in rotating Rayleigh-Benard convection. (arXiv:2311.07866v1 [physics.flu-dyn])
Furu Zhang, Jin-Han Xie

We show that the rotating Rayleigh-Benard convection, where a rotating fluid is heated from below, exhibits non-Hermitian topological states. Recently, Favier and Knobloch (JFM 2020) hypothesized that the robust wall modes in rapidly rotating convection are topologically protected. We study the linear problem around the conduction profile, and by considering a Berry curvature defined in the complex wavenumber space, particularly, by introducing a complex vertical wavenumber, we find that these modes can be characterized by a non-zero integer Chern number, indicating their topological nature. The eigenvalue problem is intrinsically non-Hermitian, therefore the definition of Berry curvature generalizes that of the stably stratified problem. Moreover, the three-dimensional setup naturally regularizes the eigenvector at the infinite horizontal wavenumber. Under the hydrostatic approximation, it recovers a two-dimensional analogue of the one which explains the topological origin of the equatorial Kelvin and Yanai waves. The existence of the tenacious wall modes relies only on rotation when the fluid is stratified, no matter whether it is stable or unstable. However, the neutrally stratified system does not support a topological edge state. In addition, we define a winding number to visualize the topological nature of the fluid.


Two-dimensional non-Hermitian skin effect in an ultracold Fermi gas. (arXiv:2311.07931v1 [cond-mat.quant-gas])
Entong Zhao, Zhiyuan Wang, Chengdong He, Ting Fung Jeffrey Poon, Ka Kwan Pak, Yu-Jun Liu, Peng Ren, Xiong-Jun Liu, Gyu-Boong Jo

The concept of non-Hermiticity has expanded the understanding of band topology leading to the emergence of counter-intuitive phenomena. One example is the non-Hermitian skin effect (NHSE), which involves the concentration of eigenstates at the boundary. However, despite the potential insights that can be gained from high-dimensional non-Hermitian quantum systems in areas like curved space, high-order topological phases, and black holes, the realization of this effect in high dimensions remains unexplored. Here, we create a two-dimensional (2D) non-Hermitian topological band for ultracold fermions in spin-orbit-coupled optical lattices with tunable dissipation, and experimentally examine the spectral topology in the complex eigenenergy plane. We experimentally demonstrate pronounced nonzero spectral winding numbers when the dissipation is added to the system, which establishes the existence of 2D skin effect. We also demonstrate that a pair of exceptional points (EPs) are created in the momentum space, connected by an open-ended bulk Fermi arc, in contrast to closed loops found in Hermitian systems. The associated EPs emerge and shift with increasing dissipation, leading to the formation of the Fermi arc. Our work sets the stage for further investigation into simulating non-Hermitian physics in high dimensions and paves the way for understanding the interplay of quantum statistics with NHSE.


Dynamical theory of topological defects II: Universal aspects of defect motion. (arXiv:2311.07970v1 [cond-mat.soft])
Jacopo Romano, Benoît Mahault, Ramin Golestanian

We study the dynamics of topological defects in continuum theories governed by a free energy minimization principle, building on our recently developed framework [Romano J, Mahault B and Golestanian R 2023 J. Stat. Mech.: Theory Exp. 083211]. We show how the equation of motion of point defects, domain walls, disclination lines and any other singularity can be understood with one unifying mathematical framework. For disclination lines, this also allows us to study the interplay between the internal line tension and the interaction with other lines. This interplay is non-trivial, allowing defect loops to expand, instead of contracting, due to external interaction. We also use this framework to obtain an analytical description of two long-lasting problems in point defect motion, namely the scale dependence of the defect mobility and the role of elastic anisotropy in the motion of defects in liquid crystals. For the former, we show that this dependence is strongly problem-dependent, but it can be computed with high accuracy for a pair of annihilating defects. For the latter, we show that at the first order in perturbation theory anisotropy causes a non-radial force, making the trajectory of annihilating defects deviate from a straight line. At higher orders, it also induces a correction in the mobility, which becomes non-isotropic for the $+1/2$ defect. We argue that, due to its generality, our method can help to shed light on the motion of singularities in many different systems, including driven and active non-equilibrium theories.


Intrinsic defect engineering of CVD grown monolayer MoS$_2$ for tuneable functional nanodevices. (arXiv:2311.07984v1 [physics.app-ph])
Irfan H. Abidi, Sindhu Priya Giridhar, Jonathan O. Tollerud, Jake Limb, Aishani Mazumder, Edwin LH Mayes, Billy J. Murdoch, Chenglong Xu, Ankit Bhoriya, Abhishek Ranjan, Taimur Ahmed, Yongxiang Li, Jeffrey A. Davis, Cameron L. Bentley, Salvy P. Russo, Enrico Della Gaspera, Sumeet Walia

Defects in atomically thin materials can drive new functionalities and expand applications to multifunctional systems that are monolithically integrated. An ability to control formation of defects during the synthesis process is an important capability to create practical deployment opportunities. Molybdenum disulfide (MoS$_2$), a two-dimensional (2D) semiconducting material harbors intrinsic defects that can be harnessed to achieve tuneable electronic, optoelectronic, and electrochemical devices. However, achieving precise control over defect formation within monolayer MoS$_2$, while maintaining the structural integrity of the crystals remains a notable challenge. Here, we present a one-step, in-situ defect engineering approach for monolayer MoS$_2$ using a pressure dependent chemical vapour deposition (CVD) process. Monolayer MoS$_2$ grown in low-pressure CVD conditions (LP-MoS$_2$) produces sulfur vacancy (Vs) induced defect rich crystals primarily attributed to the kinetics of the growth conditions. Conversely, atmospheric pressure CVD grown MoS$_2$ (AP-MoS$_2$) passivates these Vs defects with oxygen. This disparity in defect profiles profoundly impacts crucial functional properties and device performance. AP-MoS$_2$ shows a drastically enhanced photoluminescence, which is significantly quenched in LP-MoS$_2$ attributed to in-gap electron donor states induced by the Vs defects. However, the n-doping induced by the Vs defects in LP-MoS$_2$ generates enhanced photoresponsivity and detectivity in our fabricated photodetectors compared to the AP-MoS$_2$ based devices. Defect-rich LP-MoS$_2$ outperforms AP-MoS$_2$ as channel layers of field-effect transistors (FETs), as well as electrocatalytic material for hydrogen evolution reaction (HER). This work presents a single-step CVD approach for in-situ defect engineering in monolayer MoS$_2$ and presents a pathway to control defects in other monolayer material systems.


Emerging topological characterization in non-equilibrium states of quenched Kitaev chains. (arXiv:2311.08056v1 [cond-mat.str-el])
Y. B. Shi, X. Z. Zhang, Z. Song

Topological characteristics in quantum systems typically determine the ground state, while the corresponding quantum phase transition (QPT) can be identified through quenching dynamics. Based on the exact results of extended Kitaev chains, we demonstrate that the system dynamics can be comprehended through the precession of an ensemble of free-pseudo spins under a magnetic field. The topology of the driven Hamiltonian is determined by the average winding number of the non-equilibrium state. Furthermore, we establish that the singularity of the dynamical quantum phase transition (DQPT) arises from two perpendicular pseudo-spin vectors associated with the preand post-quenched Hamiltonians. Moreover, we investigate the distinct behaviors of the dynamic pairing order parameter in both topological and non-topological regions. These findings offer valuable insights into the non-equilibrium behavior of topological superconductors, contributing to the understanding of the resilience of topological properties in driven quantum systems.


Charged vacancy in graphene: interplay between Landau levels and atomic collapse resonances. (arXiv:2311.08064v1 [cond-mat.mes-hall])
Jing Wang, Wen-Sheng Zhao, Yue Hu, R. N. Costa Filho, Francois M. Peeters

The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive energy region, but in the negative energy region they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number $m$ are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same $m$, in this work anticrossing is found between the normal Landau level and the vacancy induced level. The atomic collapse resonance hybridize with the Landau levels. The charge at which the lowest Landau level $m = -1, N = 1$ crosses increases $E = 0$ with enhancing magnetic field. Landau level scaling anomaly occurs when the charge is larger than the critical charge $\beta\approx0.6$ and this critical charge is independent of the magnetic field.


Generation of electric current and electromotive force by an antiferromagnetic domain wall. (arXiv:2311.08067v1 [cond-mat.mes-hall])
A. G. Mal'shukov

Dynamic magnetic textures may transfer the angular moment from the varying in time antiferromagnetic order to spins of conduction electrons. Due to the spin orbit coupling (SOC) these spin excitations can induce the electric current of conduction electrons. We calculated the electric current and the electromotive force (EMF) which are produced by a domain wall (DW) moving parallel to the magnetically compensated interface between an antiferromagnetic insulator (AFMI) and a two-dimensional spin orbit coupled metal. Spins of conduction electrons interact with localized spins of a collinear AFMI through the interface exchange interaction. The Keldysh formalism of nonequilibrium Green functions was applied for the analysis of this system. It is shown that a Bloch DW generates the current perpendicular to the DW motion direction. At the same time a N\'{e}el DW creates the electric potential which builds up across the wall. The total charge which is pumped by a Bloch DW can be expressed in terms of a topologically invariant charge quantum. The latter does not depend on variations of DW's velocity and shape. These effects increase dramatically when the Fermi energy approaches the van Hove singularity of the Fermi surface. The obtained results are important for the electrical detection and control of dynamic magnetic textures in antiferromagnets.


Diamagnetic Susceptibility of Interacting Electrons System. (arXiv:2311.08127v1 [cond-mat.str-el])
Adam B. Cahaya

Paramagnetism or diamagnetism of a material are shown by parallel or antiparallel directions, respectively, of the induced magnetization under the influence of external magnetic field. Theoretical study of paramagnetic susceptibility and diamagnetic susceptibility of non-interacting electrons system are well described by Pauli's spin susceptibility and Landau-Peierls' orbital susceptibility, respectively. For interacting electron systems, the paramagnetic susceptibility has been widely studied by using Hubbard's electron - electron interaction. However, due to its smaller value, the diamagnetic susceptibility has not been studied. To investigate the enhancement of an interacting electrons system, we study a generalized space and time-dependent orbital susceptibility of conduction electron with a repulsive Hubbard's electron - electron interaction. By using the retarded Green function expression of the space and time-dependent orbital susceptibility, we found that the orbital susceptibility is enhanced when Hubbard's electron - electron interaction is negative.


Ultra-large polymer-free suspended graphene films. (arXiv:2311.08137v1 [physics.app-ph])
L. Kalkhoff, S. Matschy, A.S. Meyer, L. Lasnig, N. Junker, M. Mittendorff, L. Breuer, M. Schleberger

Due to its extraordinary properties, suspended graphene is a critical element in a wide range of applications. Preparation methods that preserve the unique properties of graphene are therefore in high demand. To date, all protocols for the production of large graphene films have relied on the application of a polymer film to stabilize graphene during the transfer process. However, this inevitably introduces contaminations that have proven to be extremely difficult, if not impossible, to remove entirely. Here we report the polymer-free fabrication of suspended films consisting of three graphene layers spanning circular holes of 150 $\mu$m diameter. We find a high fabrication yield, very uniform properties of the freestanding graphene across all holes as well across individual holes. A detailed analysis by confocal Raman and THz spectroscopy reveals that the triple-layer samples exhibit structural and electronic properties similar to those of monolayer graphene. We demonstrate their usability as ion-electron converters in time-of-flight mass spectrometry and related applications. They are two orders of magnitude thinner than previous carbon foils typically used in these types of experiments, while still being robust and exhibiting a sufficiently high electron yield. These results are an important step towards replacing free-standing ultra-thin carbon films or graphene from polymer-based transfers with much better defined and clean graphene.


Berry curvature induced giant intrinsic spin-orbit torque in single layer magnetic Weyl semimetal thin films. (arXiv:2311.08145v1 [cond-mat.mes-hall])
Lakhan Bainsla, Yuya Sakuraba, Keisuke Masuda, Akash Kumar, Ahmad A. Awad, Nilamani Behera, Roman Khymyn, Saroj Prasad Dash, Johan Åkerman

Topological quantum materials can exhibit unconventional surface states and anomalous transport properties, but their applications to spintronic devices are restricted as they require the growth of high-quality thin films with bulk-like properties. Here, we study 10--30 nm thick epitaxial ferromagnetic Co$_{\rm 2}$MnGa films with high structural order. Very high values of the anomalous Hall conductivity, $\sigma_{\rm xy}=1.35\times10^{5}$ $\Omega^{-1} m^{-1}$, and the anomalous Hall angle, $\theta_{\rm H}=15.8\%$, both comparable to bulk values. We observe a dramatic crystalline orientation dependence of the Gilbert damping constant of a factor of two and a giant intrinsic spin Hall conductivity, $\mathit{\sigma_{\rm SHC}}=(6.08\pm 0.02)\times 10^{5}$ ($\hbar/2e$) $\Omega^{-1} m^{-1}$, which is an order of magnitude higher than literature values of single-layer Ni$_{\rm 80}$Fe$_{\rm 20}$, Ni, Co, Fe, and multilayer Co$_{\rm 2}$MnGa stacks. Theoretical calculations of the intrinsic spin Hall conductivity, originating from a strong Berry curvature, corroborate the results and yield values comparable to the experiment. Our results open up for the design of spintronic devices based on single layers of topological quantum materials.


Angular dependence of the interlayer coupling at the interface between two dimensional materials 1T-PtSe2 and graphene. (arXiv:2311.08165v1 [cond-mat.mes-hall])
P. Mallet, F. Ibrahim, K. Abdukayumov, A. Marty, C. Vergnaud, F. Bonell, M. Chshiev, M. Jamet, J-Y Veuillen

We present a study by Scanning Tunneling Microscopy, supported by ab initio calculations, of the interaction between graphene and monolayer (semiconducting) PtSe2 as a function of the twist angle {\theta} between the two layers. We analyze the PtSe2 contribution to the hybrid interface states that develop within the bandgap of the semiconductor to probe the interaction. The experimental data indicate that the interlayer coupling increases markedly with the value of {\theta}, which is confirmed by ab initio calculations. The moir\'e patterns observed within the gap are consistent with a momentum conservation rule between hybridized states, and the strength of the hybridization can be qualitatively described by a perturbative model.


Electronic bandstructure of superconducting KTaO3 (111) interfaces. (arXiv:2311.08230v1 [cond-mat.mtrl-sci])
Srijani Mallik, Börge Göbel, Hugo Witt, Luis M.Vicente-Arche, Sara Varotto, Julien Bréhin, Gerbold Ménard, Guilhem Saïz, Dyhia Tamsaout, Andrés Felipe Santander-Syro, Franck Fortuna, François Bertran, Patrick Le Fèvre, Julien Rault, Isabella Boventer, Ingrid Mertig, Agnès Barthélémy, Nicolas Bergeal, Annika Johansson, Manuel Bibes

Two-dimensional electron gases(2DEGs)based on KTaO3 are emerging as a promising platform for spin-orbitronics due to their high Rashba spin-orbit coupling (SOC) and gate-voltage tunability. The recent discovery of a superconducting state in KTaO3 2DEGs now expands their potential towards topological superconductivity. Although the band structure of KTaO3 surfaces of various crystallographic orientations has already been mapped using angle-resolved photoemission spectroscopy(ARPES), this is not the case for superconducting KTaO3 2DEGs. Here, we reveal the electronic structure of superconducting 2DEGs based on KTaO3 (111) single crystals through ARPES measurements. We fit the data with a tight-binding model and compute the associated spin textures to bring insight into the SOC-driven physics of this fascinating system.


Non-Volatile Control of Valley Polarized Emission in 2D WSe2-AlScN Heterostructures. (arXiv:2311.08275v1 [cond-mat.mes-hall])
Simrjit Singh, Kwan-Ho Kim, Kiyoung Jo, Pariasadat Musavigharavi, Bumho Kim, Jeffrey Zheng, Nicholas Trainor, Chen Chen, Joan M. Redwing, Eric A Stach, Roy H Olsson III, Deep Jariwala

Achieving robust and electrically controlled valley polarization in monolayer transition metal dichalcogenides (ML-TMDs) is a frontier challenge for realistic valleytronic applications. Theoretical investigations show that integration of 2D materials with ferroelectrics is a promising strategy; however, its experimental demonstration has remained elusive. Here, we fabricate ferroelectric field-effect transistors using a ML-WSe2 channel and a AlScN ferroelectric dielectric, and experimentally demonstrate efficient tuning as well as non-volatile control of valley polarization. We measured a large array of transistors and obtained a maximum valley polarization of ~27% at 80 K with stable retention up to 5400 secs. The enhancement in the valley polarization was ascribed to the efficient exciton-to-trion (X-T) conversion and its coupling with an out-of-plane electric field, viz. the quantum-confined Stark effect. This changes the valley depolarization pathway from strong exchange interactions to slow spin-flip intervalley scattering. Our research demonstrates a promising approach for achieving non-volatile control over valley polarization and suggests new design principles for practical valleytronic devices.


Mott insulating negative thermal expansion perovskite TiF3. (arXiv:2311.08382v1 [cond-mat.str-el])
Donal Sheets, Kaitlin Lyszak, Menka Jain, Gayanath W. Fernando, Ilya Sochnikov, Jacob Franklin, R. Mattias Geilhufe, Jason N. Hancock

We characterize perovskite TiF_3, a material which displays significant negative thermal expansion at elevated temperatures above its cubic-to-rhombohedral structural phase transition at 330 K. We find the optical response favors an insulating state in both structural phases, which we show can be produced in density functional theory calculations only through the introduction of an on-site Coulomb repulsion. Analysis of the magnetic susceptibility data gives a S=1/2 local moment per Ti+3 ion and an antiferromagnetic exchange coupling. Together, these results show that TiF_3 is a strongly correlated electron system, a fact which constrains possible mechanisms of strong negative thermal expansion in the Sc_1-xTi_xF3 system. We consider the relative strength of the Jahn-Teller and electric dipole interactions in driving the structural transition.


Giant Resistance Switch in Twisted Transition Metal Dichalcogenide Tunnel Junctions. (arXiv:2311.08397v1 [cond-mat.mes-hall])
Marc Vila

Resistance switching in multilayer structures are typically based on materials possessing ferroic orders. Here we predict an extremely large resistance switching based on the relative spin-orbit splitting in twisted transition metal dichalcogenide (TMD) monolayers tunnel junctions. Because of the valence band spin splitting which depends on the valley index in the Brillouin zone, the perpendicular electronic transport through the junction depends on the relative reciprocal space overlap of the spin-dependent Fermi surfaces of both layers, which can be tuned by twisting one layer. Our quantum transport calculations reveal a switching resistance of up to $10^6 \%$ when the relative alignment of TMDs goes from $0^{\circ}$ to $60^{\circ}$ and when the angle is kept fixed at $60^{\circ}$ and the Fermi level is varied. By creating vacancies, we evaluate how inter-valley scattering affects the efficiency and find that the resistance switching remains large ($10^4 \%$) for typical values of vacancy concentration. Not only this resistance switching should be observed at room temperature due to the large spin splitting, but our results show how twist angle engineering and control of van der Waals heterostructures could be used for next-generation memory and electronic applications.


Anomalous pumping in the non-Hermitian Rice-Mele model. (arXiv:2110.06797v2 [cond-mat.mes-hall] UPDATED)
Abhishek Kumar, Sarbajit Mazumdar, S D Mahanti, Kush Saha

We study topological charge pumping (TCP) in the Rice-Mele (RM) model with irreciprocal hopping. The non-Hermiticity gives rise to interesting pumping physics, owing to the presence of skin effect and exceptional points. In the static 1D RM model, we observe two independent tuning knobs that drive the topological transition, viz., non-Hermitian parameter $\gamma$ and system size $N$. To elucidate the system-size dependency, we made use of the finite-size generalized Brillouin zone (GBZ) scheme. This scheme captures the state pumping of topological edge modes in the static 1D RM model and provides further insight into engineering novel gapless exceptional edge modes with the help of adiabatic drive. Finally, we apply three types of adiabatic protocols to study TCP in the 1+1D RM model. We further explain the number of pumped charges (in each period) using a non-Bloch topological invariant. This exactly explains the presence of different pumping phases in the non-Hermitian RM model as we tune the non-Hermitian parameter $\gamma$. We observe that in a non-Hermitian system, even a trivial adiabatic protocol can lead to pumping that has no Hermitian counterpart.


Ring-originated anisotropy of local structural ordering in amorphous and crystalline silicon dioxide. (arXiv:2209.12116v2 [cond-mat.mtrl-sci] UPDATED)
Motoki Shiga, Akihiko Hirata, Yohei Onodera, Hirokazu Masai

Rings comprising chemically bonded atoms are essential topological motifs for the structural ordering of network-forming materials. Quantification of such larger motifs beyond short-range pair correlation is essential for understanding the linkages between the orderings and macroscopic behaviors. Here, we propose two quantitative analysis methods based on rings. The first method quantifies rings by two geometric indicators: roundness and roughness. These indicators reveal the linkages between highly symmetric rings and crystal symmetry in silica and that the structure of amorphous silica mainly consists of distorted rings. The second method quantifies a spatial correlation function that describes three-dimensional atomic densities around rings. A comparative analysis among the functions for different degrees of ring symmetries reveals that symmetric rings contribute to the local structural order in amorphous silica. Another analysis of amorphous models with different orderings reveals anisotropy of the local structural ordering around rings; this contributes to building the intermediate-range ordering.


Transmission and conductance across junctions of isotropic and anisotropic three-dimensional semimetals. (arXiv:2302.10078v2 [cond-mat.mes-hall] UPDATED)
Ipsita Mandal

We compute the transmission coefficients and zero-temperature conductance for chiral quasiparticles propagating through various geometries, which consist of junctions of three-dimensional nodal-point semimetals. In the first scenario, we consider a potential step with two Rarita-Schwinger-Weyl or two birefringent semimetals, which are tilted with respect to the other on the two sides of the junction. The second set-up consists of a junction between a doped Dirac semimetal and a ferromagnetic Weyl semimetal, where an intrinsic magnetization present in the latter splits the doubly-degenerate Dirac node into a pair of Weyl nodes. A scalar potential is also applied in the region where the Weyl semimetal phase exists. Finally, we study sandwiches of Weyl/multi-Weyl semimetals, with the middle region being subjected to both scalar and vector potentials. Our results show that a nonzero transmission spectrum exists where the areas, enclosed by the Fermi surface projections (in the plane perpendicular to the propagation axis) of the incidence and transmission regions, overlap. Such features can help engineer unidirectional carrier propagation, topologically protected against impurity backscattering, because of the chiral nature of the charge carriers.


Orbital Hall effect in mesoscopic devices. (arXiv:2305.01640v2 [cond-mat.mes-hall] UPDATED)
Diego B. Fonseca, Lucas L. A. Pereira, Anderson L. R. Barbosa

We investigate the orbital Hall effect through a mesoscopic device with momentum-space orbital texture that is connected to four semi-infinite terminals embedded in the Landauer-B\"uttiker configuration for quantum transport. We present analytical and numerical evidence that the orbital Hall current exhibits mesoscopic fluctuations, which can be interpreted in the framework of random matrix theory (RMT) (as with spin Hall current fluctuations). The mesoscopic fluctuations of orbital Hall current display two different amplitudes of 0.36 and 0.18 for weak and strong spin-orbit coupling, respectively. The amplitudes are obtained by analytical calculation via RMT and are supported by numerical calculations based on the tight-binding model. Furthermore, the orbital Hall current fluctuations lead to two relationships between the orbital Hall angle and conductivity. Finally, we confront the two relations with experimental data of the orbital Hall angle, which shows good concordance between theory and experiment.


Gravitational anomaly in the ferrimagnetic topological Weyl semimetal NdAlSi. (arXiv:2305.04650v2 [cond-mat.mes-hall] UPDATED)
Pardeep Kumar Tanwar, Mujeeb Ahmad, Md Shahin Alam, Xiaohan Yao, Fazel Tafti, Marcin Matusiak

Quantum anomalies are the breakdowns of classical conservation laws that occur in quantum-field theory description of a physical system. They appear in relativistic field theories of chiral fermions and are expected to lead to anomalous transport properties in Weyl semimetals. This includes a chiral anomaly, which is a violation of the chiral current conservation that takes place when a Weyl semimetal is subjected to parallel electric and magnetic fields. A charge pumping between Weyl points of opposite chirality causes the chiral magnetic effect that has been extensively studied with electrical transport. On the other hand, if the thermal gradient, instead of the electrical field, is applied along the magnetic field, then as a consequence of the gravitational (also called the thermal chiral) anomaly an energy pumping occurs within a pair of Weyl cones. As a result, this is expected to generate anomalous heat current contributing to the thermal conductivity. We report an increase of both the magneto-electric and magneto-thermal conductivities in quasi-classical regime of the magnetic Weyl semimetal NdAlSi. Our work also shows that the anomalous electric and heat currents, which occur due to the chiral magnetic effect and gravitational anomalies respectively, are still linked by a 170 years old relation called the Wiedemann-Franz law.


Quantum Fractality on the Surface of Topological Insulators. (arXiv:2306.11793v2 [cond-mat.mes-hall] UPDATED)
Lakshmi Pullasseri, Daniel Shaffer, Luiz H. Santos

Three-dimensional topological insulators support gapless Dirac fermion surface states whose rich topological properties result from the interplay of symmetries and dimensionality. Their topological properties have been extensively studied in systems of integer spatial dimension but the prospect of these surface electrons arranging into structures of non-integer dimension like fractals remains unexplored. In this work, we investigate a new class of states arising from the coupling of surface Dirac fermions to a time-reversal symmetric fractal potential, which breaks translation symmetry while retaining self-similarity. Employing large-scale exact diagonalization, scaling analysis of the inverse participation ratio, and the box-counting method, we establish the onset of self-similar Dirac fermions with fractal dimension for a symmetry-preserving surface potential with the geometry of a Sierpinski carpet fractal with fractal dimension $D \approx 1.89$. Dirac fractal surface states open a fruitful avenue to explore exotic regimes of transport and quantum information storage in topological systems with fractal dimensionality.


Electronic Landscape of Kagome Superconductors $\textit{A}$V$_{3}$Sb$_{5}$ ($\textit{A}$ = K, Rb, Cs) from Angle-Resolved Photoemission Spectroscopy. (arXiv:2306.16343v2 [cond-mat.supr-con] UPDATED)
Yong Hu, Xianxin Wu, Andreas P. Schnyder, Ming Shi

The recently discovered layered kagome superconductors $\textit{A}$V$_{3}$Sb$_{5}$ ($\textit{A}$ = K, Rb, Cs) have garnered significant attention, as they exhibit an intriguing combination of superconductivity, charge density wave (CDW) order, and nontrivial band topology. As such, these kagome systems serve as an exceptional quantum platform for investigating the intricate interplay between electron correlation effects, geometric frustration, and topological electronic structure. A comprehensive understanding of the underlying electronic structure is crucial for unveiling the nature and origin of the CDW order, as well as determining the electron pairing symmetry in the kagome superconductors. In this review, we present a concise survey of the electronic properties of $\textit{A}$V$_{3}$Sb$_{5}$, with a particular focus on the insights derived from angle-resolved photoemission spectroscopy (ARPES). Through the lens of ARPES, we shed light on the electronic characteristics of the kagome superconductors $\textit{A}$V$_{3}$Sb$_{5}$, which will pave the way for exciting new research frontiers in kagome-related physics.


Shot Noise as a Diagnostic in the Fractional Quantum Hall Edge Zoo. (arXiv:2307.05173v2 [cond-mat.mes-hall] UPDATED)
Sourav Manna, Ankur Das, Moshe Goldstein

Bulk-boundary correspondence allows one to probe the bulk topological order by studying the transport properties of the edge modes. However, edge modes in a fractional quantum Hall (FQH) state can undergo edge reconstruction; moreover, they can be unequilibrated or exhibit varying degrees of charge and thermal equilibration, giving rise to a zoo of intriguing scenarios. Even more possibilities arise when a quantum point contact (QPC) is introduced and tuned into a conductance plateau. Distinguishing among the different models and equilibration regimes is an outstanding problem, which cannot be resolved by dc electrical conductance measurement. In this work we show that \emph{electrical shot noise} at a QPC conductance plateau can serve as such diagnostic. As a prototypical example we consider the $\nu=2/3$ FQH state, and show that different inequalities between the auto- and cross-correlation electrical shot noise hold for different edge models. In particular, our results offer several possible scenarios for the QPC conductance plateaus $e^2/3h$ (observed previously), $e^2/2h$ (recently observed), and $5e^2/9h$ (our prediction), as well as how to distinguish among them via shot noise.


Inter-layer valence bonds and two-component theory for high-$T_c$ superconductivity of La$_{3}$Ni$_{2}$O$_{7}$ under pressure. (arXiv:2308.01176v2 [cond-mat.supr-con] UPDATED)
Yi-feng Yang, Guang-Ming Zhang, Fu-Chun Zhang

The recent discovery of high-$T_{c}$ superconductivity in bilayer nickelate La$_{3}$Ni$_{2}$O$_{7}$ under high pressure has stimulated great interest concerning its pairing mechanism. We argue that the weak coupling model from the almost fully-filled $d_{z^{2}}$ bonding band cannot give rise to its high $T_{c}$, and thus propose a strong coupling model based on local inter-layer spin singlets of Ni-$d_{z^{2}}$ electrons due to their strong on-site Coulomb repulsion. This leads to a minimal effective model that contains local pairing of $d_{z^{2}}$ electrons and a considerable hybridization with near quarter-filled itinerant $d_{x^{2}-y^{2}}$ electrons on nearest-neighbor sites. Their strong coupling provides a unique two-component scenario to achieve high-$T_{c}$ superconductivity. Our theory highlights the importance of the bilayer structure of superconducting La$_{3}$Ni$_{2}$O$_{7}$ and points out a potential route for the exploration of more high-$T_{c}$ superconductors.


Cavity-induced switching between Bell-state textures in a quantum dot. (arXiv:2308.08722v2 [cond-mat.mes-hall] UPDATED)
S. S. Beltrán-Romero, F. J. Rodríguez, L. Quiroga, N. F. Johnson

Nanoscale quantum dots in microwave cavities can be used as a laboratory for exploring electron-electron interactions and their spin in the presence of quantized light and a magnetic field. We show how a simple theoretical model of this interplay at resonance predicts complex but measurable effects. New polariton states emerge that combine spin, relative modes, and radiation. These states have intricate spin-space correlations and undergo polariton transitions controlled by the microwave cavity field. We uncover novel topological effects involving highly correlated spin and charge density that display singlet-triplet and inhomogeneous Bell-state distributions. Signatures of these transitions are imprinted in the photon distribution, which will allow for optical read-out protocols in future experiments and nanoscale quantum technologies.


Topological marker approach to an interacting Su-Schrieffer-Heeger model. (arXiv:2308.14534v2 [cond-mat.str-el] UPDATED)
Pedro B. Melo, Sebastião A. S. Júnior, Wei Chen, Rubem Mondaini, Thereza Paiva

The topological properties of the Su-Schrieffer-Heeger (SSH) model in the presence of nearest-neighbor interaction are investigated by means of a topological marker, generalized from a noninteracting one by utilizing the single-particle Green's function of the many-body ground state. We find that despite the marker not being perfectly quantized in the presence of interactions, it always remains finite in the topologically nontrivial phase while converging to zero in the trivial phase when approaching the thermodynamic limit, and hence correctly judges the topological phases in the presence of interactions. The marker also correctly captures the interaction-driven, second-order phase transitions between a topological phase and a Landau-ordered phase, which is a charge density wave order in our model with a local order parameter, as confirmed by the calculation of entanglement entropy and the many-body Zak phase. Our work thus points to the possibility of generalizing topological markers to interacting systems through Green's function, which may be feasible for topological insulators in any dimension and symmetry class.


Direct observation and control of near-field radiative energy transfer in a natural hyperbolic material. (arXiv:2310.08351v3 [cond-mat.mes-hall] UPDATED)
L. Abou-Hamdan, A. Schmitt, R. Bretel, S. Rossetti, M. Tharrault, D. Mele, A. Pierret, M. Rosticher, T. Taniguchi, K. Watanabe, C. Maestre, C. Journet, B. Toury, V. Garnier, P. Steyer, J. H. Edgar, E. Janzen, J-M. Berroir, G. Fève, G. Ménard, B. Plaçais, C. Voisin, J-P. Hugonin, E. Bailly, B. Vest, J-J. Greffet, P. Bouchon, Y. De Wilde, E. Baudin

Heat control is a key issue in nano-electronics, where new efficient energy transfer mechanisms are highly sought after. In this respect, there is indirect evidence that high-mobility hexagonal boron nitride (hBN)-encapsulated graphene exhibits hyperbolic out-of-plane radiative energy transfer when driven out-of-equilibrium. Here we directly observe radiative energy transfer due to the hyperbolic phonon polaritons modes of the hBN encapsulant in intrinsic graphene devices under large bias, using mid-infrared spectroscopy and pyrometry. By using different hBN crystals of varied crystalline quality, we engineer the energy transfer efficiency, a key asset for compact thermal management of electronic circuits.


The Exceptional Ring of buoyancy instability in stars. (arXiv:2311.05944v1 [astro-ph.SR] CROSS LISTED)
Armand Leclerc, Lucien Jezequel, Nicolas Perez, Asmita Bhandare, Guillaume Laibe, Pierre Delplace

We reveal properties of global modes of linear buoyancy instability in stars, characterised by the celebrated Schwarzschild criterion, using non-Hermitian topology. We identify a ring of Exceptional Points of order 4 that originates from the pseudo-Hermitian and pseudo-chiral symmetries of the system. The ring results from the merging of a dipole of degeneracy points in the Hermitian stablystratified counterpart of the problem. Its existence is related to spherically symmetric unstable modes. We obtain the conditions for which convection grows over such radial modes. Those are met at early stages of low-mass stars formation. We finally show that a topological wave is robust to the presence of convective regions by reporting the presence of a mode transiting between the wavebands in the non-Hermitian problem, strengthening their relevance for asteroseismology.


Found 6 papers in prb
Date of feed: Wed, 15 Nov 2023 04:17:24 GMT

Search terms: (topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99)

Enhanced chiral edge currents and orbital magnetic moment in chiral $d$-wave superconductors from mesoscopic finite-size effects
P. Holmvall and A. M. Black-Schaffer
Author(s): P. Holmvall and A. M. Black-Schaffer

Chiral superconductors spontaneously break time-reversal symmetry and host topologically protected edge modes, supposedly generating chiral edge currents which are typically taken as a characteristic fingerprint of chiral superconductivity. However, recent studies have shown that the total edge curr…


[Phys. Rev. B 108, 174505] Published Tue Nov 14, 2023

Exact solution for finite center-of-mass momentum Cooper pairing
Chandan Setty, Jinchao Zhao, Laura Fanfarillo, Edwin W. Huang, Peter J. Hirschfeld, Philip W. Phillips, and Kun Yang
Author(s): Chandan Setty, Jinchao Zhao, Laura Fanfarillo, Edwin W. Huang, Peter J. Hirschfeld, Philip W. Phillips, and Kun Yang

Pair density waves (PDWs) are superconducting states formed by Cooper pairs of electrons containing a nonzero center-of-mass momentum. They are characterized by a spatially modulated order parameter and may occur in a variety of emerging quantum materials such as cuprates, transition-metal dichalcog…


[Phys. Rev. B 108, 174506] Published Tue Nov 14, 2023

Andreev and normal reflections in gapped bilayer graphene–superconductor junctions
Panch Ram, Detlef Beckmann, Romain Danneau, and Wolfgang Belzig
Author(s): Panch Ram, Detlef Beckmann, Romain Danneau, and Wolfgang Belzig

We study the Andreev and normal reflection processes—retro as well as specular—in a bilayer graphene–superconductor junction where equal and opposite displacement fields are applied for the top and bottom layers to induce a band gap. By employing the Dirac-Bogoliubov–de Gennes equation for the gappe…


[Phys. Rev. B 108, 184510] Published Tue Nov 14, 2023

Principle of learning sign rules by neural networks in qubit lattice models
Jin Cao, Shijie Hu, Zhiping Yin, and Ke Xia
Author(s): Jin Cao, Shijie Hu, Zhiping Yin, and Ke Xia

A neural network is a powerful tool that can uncover hidden laws beyond human intuition. However, it often appears as a black box due to its complicated nonlinear structures. By drawing upon the Gutzwiller mean-field theory, we can showcase a principle of sign rules for ordered states in qubit latti…


[Phys. Rev. B 108, 195127] Published Tue Nov 14, 2023

Quasicrystalline second-order topological semimetals
Rui Chen, Bin Zhou, and Dong-Hui Xu
Author(s): Rui Chen, Bin Zhou, and Dong-Hui Xu

Three-dimensional higher-order topological semimetals in crystalline systems exhibit higher-order Fermi arcs on one-dimensional hinges, challenging the conventional bulk-boundary correspondence. However, the existence of higher-order Fermi arc states in aperiodic quasicrystalline systems remains unc…


[Phys. Rev. B 108, 195306] Published Tue Nov 14, 2023

Klein tunneling on Bour surfaces with $N$ topological defects
Víctor A. González-Domínguez, Juan A. Reyes-Nava, and Pavel Castro-Villarreal
Author(s): Víctor A. González-Domínguez, Juan A. Reyes-Nava, and Pavel Castro-Villarreal

The existence of a curved graphene sheet with the geometry of a Bour surface ${B}_{n}$ is supposed, such as the catenoid (or helicoid), ${B}_{0}$, and the classical Enneper surface, ${B}_{2}$, among others. In particular, in this paper, the propagation of the electronic degrees of freedom on these s…


[Phys. Rev. B 108, 195421] Published Tue Nov 14, 2023

Found 1 papers in prl
Date of feed: Wed, 15 Nov 2023 04:17:26 GMT

Search terms: (topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99)

Phonon and Magnon Jets above the Critical Current in Nanowires with Planar Domain Walls
Maria Stamenova, Plamen Stamenov, and Tchavdar Todorov
Author(s): Maria Stamenova, Plamen Stamenov, and Tchavdar Todorov

We show through nonequilibrium nonadiabatic electron-spin-lattice simulations that above a critical current in magnetic atomic wires with a narrow domain wall (DW), a couple of atomic spaces in width, the electron flow triggers violent stimulated emission of phonons and magnons with an almost comple…


[Phys. Rev. Lett. 131, 206302] Published Tue Nov 14, 2023

Found 1 papers in pr_res
Date of feed: Wed, 15 Nov 2023 04:17:25 GMT

Search terms: (topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99)

Metallic nanostructures as electronic billiards for nonlinear terahertz photonics
Ihar Babushkin, Liping Shi (石理平), Ayhan Demircan, Uwe Morgner, Joachim Herrmann, and Anton Husakou
Author(s): Ihar Babushkin, Liping Shi (石理平), Ayhan Demircan, Uwe Morgner, Joachim Herrmann, and Anton Husakou

The optical properties of metallic nanoparticles are most often considered in terms of plasmons, the coupled states of light and quasifree electrons. Confinement of electrons inside the nanostructure leads to another, very different type of resonances. We demonstrate that these confinement-induced r…


[Phys. Rev. Research 5, 043151] Published Tue Nov 14, 2023

Found 14 papers in nano-lett
Date of feed: Tue, 14 Nov 2023 14:16:46 GMT

Search terms: (topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99)

[ASAP] Magnetotransport Signatures of Superconducting Cooper Pairs Carried by Topological Surface States in Bismuth Selenide
Raj Kumar, Cristian V. Ciobanu, Somilkumar J. Rathi, Joseph E. Brom, Joan M. Redwing, and Frank Hunte

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02795

[ASAP] Giant and Controllable Valley Currents in Graphene by Double Pumped THz Light
Sangeeta Sharma, Deepika Gill, and Samuel Shallcross

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02874

[ASAP] Modulating the Electrochemical Intercalation of Graphene Interfaces with α-RuCl3 as a Solid-State Electron Acceptor
Jonathon Nessralla, Daniel T. Larson, Takashi Taniguchi, Kenji Watanabe, Efthimios Kaxiras, and D. Kwabena Bediako

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02877

[ASAP] Gate-Tuning Hybrid Polaritons in Twisted α-MoO3/Graphene Heterostructures
Zhou Zhou, Renkang Song, Junbo Xu, Xiang Ni, Zijia Dang, Zhichen Zhao, Jiamin Quan, Siyu Dong, Weida Hu, Di Huang, Ke Chen, Zhanshan Wang, Xinbin Cheng, Markus B. Raschke, Andrea Alù, and Tao Jiang

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Nano Letters
DOI: 10.1021/acs.nanolett.3c03769

[ASAP] Nanoparticle Deep-Subwavelength Dynamics Empowered by Optical Meron–Antimeron Topology
Chengfeng Lu, Bo Wang, Xiang Fang, Din Ping Tsai, Weiming Zhu, Qinghua Song, Xiao Deng, Tao He, Xiaoyun Gong, Hong Luo, Zhanshan Wang, Xinhua Dai, Yuzhi Shi, and Xinbin Cheng

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Nano Letters
DOI: 10.1021/acs.nanolett.3c03351

[ASAP] Graphene Oxide-Mediated Regulation of Volume Exclusion and Wettability in Biomimetic Phosphorylation-Responsive Ionic Gates
Liu Shi, Beibei Nie, Lingjun Sha, Keqin Ying, Jinlong Li, and Genxi Li

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02924

[ASAP] PZT-Enabled MoS2 Floating Gate Transistors: Overcoming Boltzmann Tyranny and Achieving Ultralow Energy Consumption for High-Accuracy Neuromorphic Computing
Jing Chen, Ye-Qing Zhu, Xue-Chun Zhao, Zheng-Hua Wang, Kai Zhang, Zheng Zhang, Ming-Yuan Sun, Shuai Wang, Yu Zhang, Lin Han, Xiaoming Wu, and Tian-Ling Ren

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02721

[ASAP] Topological Transitions and Surface Umklapp Scattering in Weakly Modulated Periodic Metasurfaces
Kobi Cohen, Shai Tsesses, Shimon Dolev, Yael Blechman, Guy Ankonina, and Guy Bartal

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02759

[ASAP] High-Performance WSe2 Top-Gate Devices with Strong Spacer Doping
Po-Hsun Ho, Yu-Ying Yang, Sui-An Chou, Ren-Hao Cheng, Po-Heng Pao, Chao-Ching Cheng, Iuliana Radu, and Chao-Hsin Chien

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.3c02757

[ASAP] Robustness of Trion State in Gated Monolayer MoSe2 under Pressure
Zeya Li, Feng Qin, Chin Shen Ong, Junwei Huang, Zian Xu, Peng Chen, Caiyu Qiu, Xi Zhang, Caorong Zhang, Xiuxiu Zhang, Olle Eriksson, Angel Rubio, Peizhe Tang, and Hongtao Yuan

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02812

[ASAP] Unveiling Local Optical Properties Using Nanoimaging Phase Mapping in High-Index Topological Insulator Bi2Se3 Resonant Nanostructures
Sukanta Nandi, Shany Z. Cohen, Danveer Singh, Michal Poplinger, Pilkhaz Nanikashvili, Doron Naveh, and Tomer Lewi

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Nano Letters
DOI: 10.1021/acs.nanolett.3c03128

[ASAP] Electric Potential at the Interface of Membraneless Organelles Gauged by Graphene
Christian Hoffmann, Gennadiy Murastov, Johannes Vincent Tromm, Jean-Baptiste Moog, Muhammad Awais Aslam, Aleksandar Matkovic, and Dragomir Milovanovic

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.3c02915

[ASAP] Semiconducting Transition Metal Dichalcogenide Heteronanotubes with Controlled Outer-Wall Structures
Yohei Yomogida, Mai Nagano, Zheng Liu, Kan Ueji, Md. Ashiqur Rahman, Abdul Ahad, Akane Ihara, Hiroyuki Nishidome, Takashi Yagi, Yusuke Nakanishi, Yasumitsu Miyata, and Kazuhiro Yanagi

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.3c01761

[ASAP] Submillimeter-Long WS2 Nanotubes: The Pathway to Inorganic Buckypaper
Vojtěch Kundrát, Rita Rosentsveig, Kristýna Bukvišová, Daniel Citterberg, Miroslav Kolíbal, Shachar Keren, Iddo Pinkas, Omer Yaffe, Alla Zak, and Reshef Tenne

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Nano Letters
DOI: 10.1021/acs.nanolett.3c02783

Found 3 papers in acs-nano
Date of feed: Tue, 14 Nov 2023 14:12:16 GMT

Search terms: (topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99)

[ASAP] Analysis of Strain and Defects in Tellurium-WSe2 Moiré Heterostructures Using Scanning Nanodiffraction
Bengisu Sari, Steven E. Zeltmann, Chunsong Zhao, Philipp M. Pelz, Ali Javey, Andrew M. Minor, Colin Ophus, and Mary C. Scott

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c04283

[ASAP] Strain-Induced 2H to 1T′ Phase Transition in Suspended MoTe2 Using Electric Double Layer Gating
Shubham Sukumar Awate, Ke Xu, Jierui Liang, Benjamin Katz, Ryan Muzzio, Vincent H. Crespi, Jyoti Katoch, and Susan K. Fullerton-Shirey

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ACS Nano
DOI: 10.1021/acsnano.3c04701

[ASAP] Graphene-In2Se3 van der Waals Heterojunction Neuristor for Optical In-Memory Bimodal Operation
Subhrajit Mukherjee, Debopriya Dutta, Anurag Ghosh, and Elad Koren

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ACS Nano
DOI: 10.1021/acsnano.3c03820

Found 1 papers in nat-comm


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Bulk-local-density-of-state correspondence in topological insulators
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