Found 39 papers in cond-mat
Date of feed: Wed, 01 Nov 2023 00:30:00 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)

Tight-binding theory of spin-spin interactions, Curie temperatures, and quantum Hall effects in topological (Hg,Cr)Te in comparison to non-topological (Zn,Cr)Te, and (Ga,Mn)N. (arXiv:2310.19856v1 [cond-mat.mtrl-sci])
Cezary Śliwa, Tomasz Dietl

Earlier theoretical results on $p$-$d$ and $d$-$d$ exchange interactions for zinc-blende semiconductors with Cr$^{2{+}}$ and Mn$^{3{+}}$ ions are revisited and extended by including contributions beyond the dominating ferromagnetic (FM) superexchange term [i.e., the interband Bloembergen-Rowland-Van Vleck contribution and antiferromagnetic (AFM) two-electron term], and applied to topological Cr-doped HgTe and non-topological (Zn,Cr)Te and (Ga,Mn)N in zinc-blende and wurtzite crystallographic structures. From the obtained values of the $d$-$d$ exchange integrals $J_{ij}$, and by combining the Monte-Carlo simulations with the percolation theory for randomly distributed magnetic ions, we determine magnitudes of Curie temperatures $T_{\text{C}}(x)$ for $\mathrm{Zn}_{1-x}\mathrm{Cr}_x\mathrm{Te}$ and $\mathrm{Ga}_{1-x}\mathrm{Mn}_x\mathrm{N}$ and compare to available experimental data. Furthermore, we find that competition between FM and AFM $d$-$d$ interactions can lead to a spin-glass phase in the case of $\mathrm{Hg}_{1-x}\mathrm{Cr}_x\mathrm{Te}$. This competition, along with a relatively large magnitude of the AF $p$-$d$ exchange energy $N_0\beta$ can stabilize the quantum spin Hall effect, but may require the application of a tilted magnetic field to observe the quantum anomalous Hall effect in HgTe quantum wells doped with Cr.

Self-duality under gauging a non-invertible symmetry. (arXiv:2310.19867v1 [hep-th])
Yichul Choi, Da-Chuan Lu, Zhengdi Sun

We discuss two-dimensional conformal field theories (CFTs) which are invariant under gauging a non-invertible global symmetry. At every point on the orbifold branch of $c=1$ CFTs, it is known that the theory is self-dual under gauging a $\mathbb{Z}_2 \times \mathbb{Z}_2$ symmetry, and has $\mathsf{Rep}(H_8)$ and $\mathsf{Rep}(D_8)$ fusion category symmetries as a result. We find that gauging the entire $\mathsf{Rep}(H_8)$ fusion category symmetry maps the orbifold theory at radius $R$ to that at radius $2/R$. At $R=\sqrt{2}$, which corresponds to two decoupled Ising CFTs (Ising$^2$ in short), the theory is self-dual under gauging the $\mathsf{Rep}(H_8)$ symmetry. This implies the existence of a new topological defect line in the Ising$^2$ CFT obtained from half-space gauging of the $\mathsf{Rep}(H_8)$ symmetry, which commutes with the $c=1$ Virasoro algebra but does not preserve the fully extended chiral algebra. We bootstrap its action on the $c=1$ Virasoro primary operators, and find that there are no relevant or marginal operators preserving it. Mathematically, the new topological line combines with the $\mathsf{Rep}(H_8)$ symmetry to form a bigger fusion category which is a $\mathbb{Z}_2$-extension of $\mathsf{Rep}(H_8)$. We solve the pentagon equations including the additional topological line and find 8 solutions, where two of them are realized in the Ising$^2$ CFT. Finally, we show that the torus partition functions of the Monster$^2$ CFT and Ising$\times$Monster CFT are also invariant under gauging the $\mathsf{Rep}(H_8)$ symmetry.

Connecting the avoided quantum critical point to the magic-angle transition in three-dimensional Weyl semimetals. (arXiv:2310.19876v1 [cond-mat.dis-nn])
J. H. Pixley, David A. Huse, Justin H. Wilson

We theoretically study the interplay of short-ranged random and quasiperiodic static potentials on the low-energy properties of three-dimensional Weyl semimetals. This setting allows us to investigate the connection between the semimetal to diffusive metal "magic-angle" phase transition due to quasiperiodicity and the rare-region induced crossover at an avoided quantum critical point (AQCP) due to disorder. We show that in the presence of both random and quasiperiodic potentials the AQCP becomes lines of crossovers, which terminate at magic-angle critical points in the quasiperiodic, disorder-free limit. We analyze the magic-angle transition by approaching it along these lines of avoided transitions, which unveils a rich miniband structure and several AQCPs. These effects can be witnessed in cold-atomic experiments through potential engineering on semimetallic band structures.

Magnetotransport in spin-orbit coupled noncentrosymmetric and Weyl metals. (arXiv:2310.19877v1 [cond-mat.mes-hall])
Gautham Varma K, Azaz Ahmad, Sumanta Tewari, G. Sharma

Recently, chiral anomaly (CA) has been proposed to occur in spin-orbit coupled noncentrosymmetric metals (SOC-NCMs), motivating CA to be a Fermi surface property rather than a Weyl node property. Although the nature of the anomaly is similar in both SOC-NCMs and Weyl systems, here we point out significant fundamental differences between the two. We show that the different nature of the orbital magnetic moment (OMM) in the two systems leads to non-trivial consequences -- particularly the sign of the longitudinal magnetoconductance always remains positive in a SOC non-centrosymmetric metal, unlike a Weyl metal that displays either sign. Furthermore,we investigate the planar Hall effect and the geometrical contribution to the Hall effect in the two systems and point out significant differences in the two systems. We conduct our analysis for magnetic and non-magnetic impurities, making our study important in light of current and upcoming experiments in both SOC-NCMs and Weyl metals.

Electrical Tuning of Neutral and Charged Excitons with 1-nm Gate. (arXiv:2310.19895v1 [cond-mat.mes-hall])
Jawaher Almutlaq (1), Jiangtao Wang (2), Linsen Li (1), Chao Li (1), Tong Dang (2), Vladimir Bulović (2), Jing Kong (2), Dirk Englund (1)

Electrical control of individual spins and photons in solids is key for quantum technologies, but scaling down to small, static systems remains challenging. Here, we demonstrate nanoscale electrical tuning of neutral and charged excitons in monolayer WSe2 using 1-nm carbon nanotube gates. Electrostatic simulations reveal a confinement radius below 15 nm, reaching the exciton Bohr radius limit for few-layer dielectric spacing. In situ photoluminescence spectroscopy shows gate-controlled conversion between neutral excitons, negatively charged trions, and biexcitons at 4 K. Important for quantum information processing applications, our measurements indicate gating of a local 2D electron gas in the WSe2 layer, coupled to photons via trion transitions with binding energies exceeding 20 meV. The ability to deterministically tune and address quantum emitters using nanoscale gates provides a pathway towards large-scale quantum optoelectronic circuits and spin-photon interfaces for quantum networking.

Non-bosonic moir\'e excitons. (arXiv:2310.19931v1 [cond-mat.mes-hall])
Tsung-Sheng Huang, Peter Lunts, Mohammad Hafezi

Optical excitations in moir\'e transition metal dichalcogenide bilayers lead to the creation of excitons, as electron-hole bound states, that are generically considered within a Bose-Hubbard framework. Here, we demonstrate that these composite particles obey an angular momentum commutation relation that is generally non-bosonic. This emergent spin description of excitons indicates a limitation to their occupancy on each site, which is substantial in the weak electron-hole binding regime. The effective exciton theory is accordingly a spin Hamiltonian, which further becomes a Hubbard model of emergent bosons subject to an occupancy constraint after a Holstein-Primakoff transformation. We apply our theory to three commonly studied bilayers (MoSe2/WSe2, WSe2/WS2, and WSe2/MoS2) and show that in the relevant parameter regimes their allowed occupancies never exceed three excitons. Our systematic theory provides guidelines for future research on the many-body physics of moir\'e excitons.

Electron Interactions in Rashba Materials. (arXiv:2310.20084v1 [cond-mat.supr-con])
Yasha Gindikin, Alex Kamenev

We show that Rashba spin-orbit coupling modifies electron-electron interaction vertex leading to a number of novel phenomena. First, the spin-orbit-modified Coulomb interactions induce p-wave superconducting order, without any other mediators of attraction. Second, a sufficiently strong spin-orbit coupling results in a ferromagnetic order, associated with a Lifshitz transition from a spherical to a toroidal Fermi surface. Such topology-changing transition leads to distinct experimentally observable consequences. Finally, in sufficiently clean Rashba materials, the ferromagnetism may coexist with the p-wave superconductivity.

Rashba spin splitting based on trilayer graphene systems. (arXiv:2310.20136v1 [cond-mat.mes-hall])
Xinjuan Cheng, Liangyao Xiao, Xuechao Zhai

We establish a general Rashba Hamiltonian for trilayer graphene (TLG) by introducing an extrinsic layer-dependent Rashba spin-orbit coupling (SOC) arising from the off-plane inversion symmetry breaking. Our results indicate that the band spin splitting depends strongly on the layer-distribution and sign of Rashba SOC as well as the ABA or ABC stacking order of TLG. We find that spin splitting is significantly enhanced as the number of layers of the Rashba SOC with the same sign and magnitude increases. For the spatially-separated two Rashba SOCs of the same magnitude but the opposite sign, no spin splitting arises in ABC-TLG due to the preservation of inversion symmetry that ensures the complete cancellation of contributions from the opposite layers, whereas nonzero spin splitting is observed for ABA-TLG due to its own lack of inversion symmetry. We further illustrate that gate voltage is effective to modulate the spin-polarized states near the band edges. Moreover, we use density functional theory calculations to verify the Rashba splitting effect in the example of TLG interfaced by Au layer(s), which induce simultaneously the effective terms of Rashba SOC and gate voltage. Our results demonstrate the significance of layer and symmetry in manipulating spin and can be extended to multilayer graphene or other van der Waals interface systems.

Tunnel Valley Current Filter in the Partially Overlapped Graphene under the Vertical Electric Field. (arXiv:2310.20139v1 [cond-mat.mes-hall])
Ryo Tamura

The tunnel current (TC) and valley current (VC) are crucial in realizing high-speed and energy-saving in next-generation devices. This paper presents the TC and VC link in the partially overlapped graphene. Under the vertical electric field, the two graphene layers have the opposite AB sublattice symmetry, followed by a block on the intravalley transmission. In the allowed intervalley transmission, the difference in the phase of the decay factor prefers only one of the valleys in the output according to the overlapped length. These results suggest that the band gap with no edge state is a new platform of valleytronics.

Low-dimensional polaritonics: Emergent non-trivial topology on exciton-polariton simulators. (arXiv:2310.20166v1 [cond-mat.mes-hall])
Konstantin Rips

Polaritonic lattice configurations in dimensions $D=2$ are used as simulators of topological phases, based on symmetry class A Hamiltonians. Numerical and topological studies are performed in order to characterise the bulk topology of insulating phases, which is predicted to be connected to non-trivial edge mode states on the boundary. By using spectral flattened Hamiltonians on specific lattice geometries with time reversal symmetry breaking, e.g. Kagome lattice, we obtain maps from the Brillouin zone into Grassmannian spaces, which are further investigated by the topological method of space fibrations. Numerical evidence reveals a connection between the sum of valence band Chern numbers and the index of the projection operator onto the valence band states. Along these lines, we discover an index formula which resembles other index theorems and the classical result of Atiyah-Singer, but without any Dirac operator and from a different perspective. Through a combination of different tools, in particular homotopy and homology-cohomology duality, we provide a comprehensive mathematical framework, which fully addresses the source and structure of topological phases in coupled polaritonic array systems. Based on these results, it becomes possible to infer further designs and models of two-dimensional single sheet Chern insulators, implemented as polariton simulators.

Phase-Modulated Elastic Properties of Two-Dimensional Magnetic FeTe: Hexagonal and Tetragonal Polymorphs. (arXiv:2310.20167v1 [cond-mat.mtrl-sci])
Yunfei Yu, Mo Cheng, Zicheng Tao, Wuxiao Han, Guoshuai Du, Yanfeng Guo, Jianping Shi, Yabin Chen

Two-dimensional (2D) layered magnets, such as iron chalcogenides, have emerged these years as a new family of unconventional superconductor and provided the key insights to understand the phonon-electron interaction and pairing mechanism. Their mechanical properties are of strategic importance for the potential applications in spintronics and optoelectronics. However, there is still lack of efficient approach to tune the elastic modulus despite the extensive studies. Herein, we report the modulated elastic modulus of 2D magnetic FeTe and its thickness-dependence via phase engineering. The grown 2D FeTe by chemical vapor deposition can present various polymorphs, i.e. tetragonal FeTe (t-FeTe, antiferromagnetic) and hexagonal FeTe (h-FeTe, ferromagnetic). The measured Young's modulus of t-FeTe by nanoindentation method showed an obvious thickness-dependence, from 290.9+-9.2 to 113.0+-8.7 GPa when the thicknesses increased from 13.2 to 42.5 nm, respectively. In comparison, the elastic modulus of h-FeTe remains unchanged. Our results could shed light on the efficient modulation of mechanical properties of 2D magnetic materials and pave the avenues for their practical applications in nanodevices.

Topological speckles. (arXiv:2310.20213v1 [physics.optics])
Yure M. I. A. Rodrigues, Matheus F. V. Oliveira, Andre M. C. Souza, Marcelo L. Lyra, Francisco A. B. F. de Moura, Guilherme M. A. Almeida

The time evolution of a topological Su-Schrieffer-Heeger chain is analyzed through the statistics of speckle patterns. The emergence of topological edge states dramatically affects the dynamical fluctuations of the wavefunction. The intensity statistics is found to be described by a family of noncentral chi-squared distributions, with the noncentrality parameter reflecting on the degree of edge-state localization. The response of the speckle contrast with respect to the dimerization of the chain is explored in detail as well as the role of chiral symmetry-breaking disorder, number of edge states, their energy gap, and the locations between which the transport occurs. In addition to providing a venue for speckle customization, our results appeal to the use of speckle patterns for characterization of nontrivial topological properties.

Dissipation entanglement control of two coupled qubits via strong driving fields. (arXiv:2310.20229v1 [quant-ph])
M. V. Bastrakova, V. O. Munyaev

An analytical theory to calculate the dissipatively stable concurrence in the system of two coupled flux superconducting qubits in the strong driving field is developed. The conditions for the entanglement state generation and destruction during the formation of the multiphoton transitions regions due to the interference of Landau--Zener--St\"uckelberg--Majorana are found. Based on the solution of the Floquet--Markov equation, the technique is proposed to adjust the amplitudes of dc- and ac-fields for effective control of the entanglement between qubit states while taking into account the effects of the decoherence.

Enhanced dendrite nucleation and Li-clustering at vacancies on graphene. (arXiv:2310.20241v1 [cond-mat.mtrl-sci])
Jonathon Cottom, Qiong Cai, Emilia Olsson

An ever present challenge for Li-ion batteries is the formation of metallic dendrites on cycling that dramatically reduces cycle life and leads to the untimely failure of the cell. In this work we investigate the modes of Li-cluster formation on pristine and defective graphene. Firstly, we demonstrate that on a defect free surface the cluster formation is impeded by the thermodynamic instability of \ce{Li_2} and \ce{Li_3} clusters. In contrast, the presence of a vacancy dramatically favours clustering. This provides insights into the two modes of Li-growth observed: for the pristine basal plane if the Li-Li repulsion of the small clusters can be overcome then plating type behaviour would be predicted (rate / voltage dependent and at any point on the surface); whilst dendritic growth would be predicted to nucleate from vacancy sites, either pre-existing in the material or formed as a result of processing.

Topological plasma transport from a diffusion view. (arXiv:2310.20244v1 [physics.plasm-ph])
Zhoufei Liu, Jiping Huang

Recent studies have identified plasma as a topological material. Yet, these researches often depict plasma as a fluid governed by electromagnetic fields, i.e., a classical wave system. Indeed, plasma transport can be characterized by a unique diffusion process distinguished by its collective behaviors. In this work, we adopt a simplified diffusion-migration method to elucidate the topological plasma transport. Drawing parallels to the thermal conduction-convection system, we introduce a double ring model to investigate the plasma density behaviors in the anti-parity-time reversal (APT) unbroken and broken phases. Subsequently, by augmenting the number of rings, we have established a coupled ring chain structure. This structure serves as a medium for realizing the APT symmetric one-dimensional (1D) reciprocal model, representing the simplest tight-binding model with a trivial topology. To develop a model featuring topological properties, we should modify the APT symmetric 1D reciprocal model from the following two aspects: hopping amplitude and onsite potential. From the hopping amplitude, we incorporate the non-reciprocity to facilitate the non-Hermitian skin effect, an intrinsic non-Hermitian topology. Meanwhile, from the onsite potential, the quasiperiodic modulation has been adopted onto the APT symmetric 1D reciprocal model. This APT symmetric 1D Aubry-Andr\'e-Harper model is of topological nature. Additionally, we suggest the potential applications for these diffusive plasma topological states. This study establishes a diffusion-based approach to realizing topological states in plasma, potentially inspiring further advancements in plasma physics.

Emergent topological ordered phase for the Ising-XY Model revealed by cluster-updating Monte-Carlo method. (arXiv:2310.20314v1 [cond-mat.quant-gas])
Heyang Ma, Wanzhou Zhang, Chengxiang Ding, Youjin Deng

The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy. At low temperatures, theoretical predictions [Phys. Rev. A 72, 053604 (2005)] and [arXiv:0706.1609] indicate the existence of a topological ordered phase characterized by Ising and XY disorder but with 2XY ordering. However, due to ergodic difficulties faced by Monte Carlo methods at low temperatures, this topological phase has not been numerically explored. We propose a linear cluster updating Monte Carlo method, which flips spins without rejection in the anisotropy limit but does not change the energy. Using this scheme and conventional Monte Carlo methods, we succeed in revealing the nature of topological phases with half-vortices and domain walls. In the constructed global phase diagram, Ising and XY type transitions are very close to each other and differ significantly from the schematic phase diagram reported earlier. We also propose and explore a wide range of quantities, including magnetism, superfluidity, specific heat, susceptibility, and even percolation susceptibility, and obtain consistent results. Furthermore, we observe first-order transitions characterized by common intersection points in magnetizations for different system sizes, as opposed to the conventional phase transition where Binder cumulants of various sizes share common intersections. The results are useful to help cold atom experiments explore the half-vortex topological phase.

de Haas-van Alphen spectroscopy and fractional quantization of magnetic-breakdown orbits in moir\'e graphene. (arXiv:2310.20338v1 [cond-mat.mes-hall])
Matan Bocarsly, Matan Uzan, Indranil Roy, Sameer Grover, Jiewen Xiao, Zhiyu Dong, Mikhail Labendik, Aviram Uri, Martin E. Huber, Yuri Myasoedov, Kenji Watanabe, Takashi Taniguchi, Binghai Yan, Leonid S. Levitov, Eli Zeldov

Quantum oscillations originating from the quantization of the electron cyclotron orbits provide ultrasensitive diagnostics of electron bands and interactions in novel materials. We report on the first direct-space nanoscale imaging of the thermodynamic magnetization oscillations due to the de Haas-van Alphen effect in moir\'e graphene. Scanning by SQUID-on-tip in Bernal bilayer graphene crystal-axis-aligned to hBN reveals abnormally large magnetization oscillations with amplitudes reaching 500 {\mu}_B/electron in weak magnetic fields, unexpectedly low frequencies, and high sensitivity to the superlattice filling fraction. The oscillations allow us to reconstruct the complex band structure in exquisite detail, revealing narrow moir\'e bands with multiple overlapping Fermi surfaces separated by unusually small momentum gaps. We identify distinct sets of oscillations that violate the textbook Onsager Fermi surface sum rule, signaling formation of exotic broad-band particle-hole superposition states induced by coherent magnetic breakdown.

Signature of Dirac Semimetal in Harmonic-honeycomb ReO3. (arXiv:2310.20341v1 [cond-mat.mtrl-sci])
Yifeng Han, Cuiqun Chen, Hualei Sun, Shuang Zhao, Long Jiang, Yuxuan Liu, Zhongxiong Sun, Meng Wang, Hongliang Dong, Ziyou Zhang, Zhiqiang Chen, Bin Chen, Dao-Xin Yao, Man-Rong Li

Transition-metal honeycomb compounds are capturing scientific attention due to their distinctive electronic configurations, underscored by the triangular-lattice spin-orbit coupling and competition between multiple interactions, paving the way for potential manifestations of phenomena such as Dirac semimetal, superconductivity, and quantum spin liquid states. These compounds can undergo discernible pressure-induced alterations in their crystallographic and electronic paradigms, as exemplified by our high-pressure (HP) synthesis and exploration of the honeycomb polymorph of ReO3 (P6322). This HP-P6322 polymorph bears a phase transition from P6322 to P63/mmc upon cooling around Tp = 250 K, as evidenced by the evolution of temperature-dependent magnetization (M-T curves), cell dimension, and conductivity initiated by an inherent bifurcation of the oxygen position in the ab plane. Insightful analysis of its band structure positions suggests this HP-P6322 polymorph being a plausible candidate for Dirac semimetal properties. This phase transition evokes anomalies in the temperature-dependent variation of paramagnetism (non-linearity) and a crossover from semiconductor to temperature-independent metal, showing a temperature independent conductivity behavior below ~200 K. Under increasing external pressure, both the Tp and resistance of this HP-polymorph is slightly magnetic-field dependent and undergo a "V"-style evolution (decreasing and then increasing) before becoming pressure independent up to 20.2 GPa. Theoretical calculations pinpoint this anionic disorder as a probable catalyst for the decrement in the conductive efficiency and muted temperature-dependent conductivity response.

Chiral charge density wave and backscattering-immune orbital texture in monolayer 1T-TiTe2. (arXiv:2310.20373v1 [cond-mat.mtrl-sci])
Mingqiang Ren, Fangjun Cheng, Yufei Zhao, Mingqiang Gu, Qiangjun Cheng, Binghai Yan, Qihang Liu, Xucun Ma, Qikun Xue, Can-Li Song

Non-trivial electronic states are attracting intense attention in low-dimensional physics. Though chirality has been identified in charge states with a scalar order parameter, its intertwining with charge density waves (CDW), film thickness and the impact on the electronic behaviors remain less well understood. Here, using scanning tunneling microscopy, we report a 2 x 2 chiral CDW as well as a strong suppression of the Te-5p hole-band backscattering in monolayer 1T-TiTe2. These exotic characters vanish in bilayer TiTe2 with a non-CDW state. Theoretical calculations approve that chirality comes from a helical stacking of the triple-q CDW components and therefore can persist at the two-dimensional limit. Furthermore, the chirality renders the Te-5p bands an unconventional orbital texture that prohibits electron backscattering. Our study establishes TiTe2 as a promising playground for manipulating the chiral ground states at the monolayer limit and provides a novel path to engineer electronic properties from an orbital degree.

Intercellular Friction and Motility Drive Orientational Order in Cell Monolayers. (arXiv:2310.20465v1 [cond-mat.soft])
Michael Chiang, Austin Hopkins, Benjamin Loewe, M. Cristina Marchetti, Davide Marenduzzo

Spatiotemporal patterns in multicellular systems are important to understanding tissue dynamics, for instance, during embryonic development and disease. Here, we use a multiphase field model to study numerically the behavior of a near-confluent monolayer of deformable cells with intercellular friction. Varying friction and cell motility drives a solid-liquid transition, and near the transition boundary, we find the emergence of nematic order of cell deformation driven by shear-aligning cellular flows. Intercellular friction endows the monolayer with a finite viscosity, which significantly increases the spatial correlation in the flow and, concomitantly, the extent of nematic order. We also show that hexatic and nematic order are tightly coupled and propose a mechanical-geometric model for the colocalization of +1/2 nematic defects and 5-7 disclination pairs, which are the structural defects in the hexatic phase. Such topological defects coincide with regions of high cell-cell overlap, suggesting that they may mediate cellular extrusion from the monolayer, as found experimentally. Our results delineate a mechanical basis for the recent observation of nematic and hexatic order in multicellular collectives in experiments and simulations and pinpoint a generic pathway to couple topological and physical effects in these systems.

Hidden Real Topology and Unusual Magnetoelectric Responses in Monolayer Antiferromagnetic Cr$_2$Se$_2$O. (arXiv:2310.20510v1 [cond-mat.mtrl-sci])
Jialin Gong, Yang Wang, Yilin Han, Zhenxiang Cheng, Xiaotian Wang, Zhi-Ming Yu, Yugui Yao

Recently, the real topology has been attracting widespread interest in two dimensions (2D). Here, based on first-principles calculations and theoretical analysis, we reveal the monolayer Cr$_2$Se$_2$O (ML-CrSeO) as the first material example of a 2D antiferromagnetic (AFM) real Chern insulator (RCI) with topologically protected corner states. Unlike previous RCIs, we find that the real topology of the ML-CrSeO is rooted in one certain mirror subsystem of the two spin channels, and can not be directly obtained from all the valence bands in each spin channel as commonly believed. In particular, due to antiferromagnetism, the corner modes in ML-CrSeO exhibit strong corner-contrasted spin polarization, leading to spin-corner coupling (SCC). This SCC enables a direct connection between spin space and real space. Consequently, large and switchable net magnetization can be induced in the ML-CrSeO nanodisk by electrostatic means, such as potential step and in-plane electric field, and the corresponding magnetoelectric responses behave like a sign function, distinguished from that of the conventional multiferroic materials. Our work considerably broadens the candidate range of RCI materials, and opens up a new direction for topo-spintronics and 2D AFM materials research.

Berry Curvature Dipole and its Strain Engineering in Layered Phosphorene. (arXiv:2310.20543v1 [cond-mat.mes-hall])
Arka Bandyopadhyay, Nesta Benno Joseph, Awadhesh Narayan

The emergence of the fascinating non-linear Hall effect intrinsically depends on the non-zero value of the Berry curvature dipole. In this work, we predict that suitable strain engineering in layered van der Waals material phosphorene can give rise to a significantly large Berry curvature dipole. Using symmetry design principles, and a combination of feasible strain and staggered on-site potentials, we show how a substantial Berry curvature dipole may be engineered at the Fermi level. We discover that monolayer phosphorene exhibits the most intense Berry curvature dipole peak near 11.8% strain, which is also a critical point for the topological phase transition in pristine phosphorene. Furthermore, we have shown that the necessary strain value to achieve substantial Berry curvature dipole can be reduced by increasing the number of layers. We have revealed that strain in these van der Waals systems not only alters the magnitude of Berry curvature dipole to a significant value but allows control over its sign. We are hopeful that our predictions will pave way to realize the non-linear Hall effect in such elemental van der Waals systems.

Finite Temperature Entanglement Negativity of Fermionic Symmetry Protected Topological Phases and Quantum Critical Points in One Dimension. (arXiv:2310.20566v1 [cond-mat.str-el])
Wonjune Choi, Michael Knap, Frank Pollmann

We study the logarithmic entanglement negativity of symmetry-protected topological (SPT) phases and quantum critical points (QCPs) of one-dimensional noninteracting fermions at finite temperatures. In particular, we consider a free fermion model that realizes not only quantum phase transitions between gapped phases but also an exotic topological phase transition between quantum critical states in the form of the fermionic Lifshitz transition. We find that the bipartite entanglement negativity between adjacent fermion blocks reveals the crossover boundary of the quantum critical fan near the QCP between two gapped phases. Along the critical phase boundary between the gapped phases, the sudden decrease in the entanglement negativity signals the fermionic Lifshitz transition responsible for the change in the topological nature of the QCPs. In addition, the tripartite entanglement negativity between spatially separated fermion blocks counts the number of topologically protected boundary modes for both SPT phases and topologically nontrivial QCPs at zero temperature. However, the long-distance entanglement between the boundary modes vanishes at finite temperatures due to the instability of SPTs, the phases themselves.

Proximity effect induced intriguing superconductivity in van der Waals heterostructure of magnetic topological insulator and conventional superconductor. (arXiv:2310.20576v1 [cond-mat.supr-con])
Peng Dong, Xiang Zhou, Xiaofei Hou, Jiadian He, Yiwen Zhang, Yifan Ding, Xiaohui Zeng, Jinghui Wang, Yueshen Wu, Kenji Watanabe, Takashi Taniguchi, Wei Xia, Yanfeng Guo, Yulin Chen, Wei Li, Jun Li

Nontrivial topological superconductivity has received enormous research attentions due to its potential for diverse applications in topological quantum computing. The intrinsic issue concerning the correlation between a topological insulator and a superconductor is, however, still widely open. Here, we systemically report an emergent superconductivity in a cross-junction composed of a magnetic topological insulator MnBi2Te4 and a conventional superconductor NbSe2. Remarkably, the interface indicates existence of a reduced superconductivity at surface of NbSe2 and a proximity-effectinduced superconductivity at surface of MnBi2Te4. Furthermore, the in-plane angular-dependent magnetoresistance measurements reveal the fingerprints of the paring symmetry behaviors for these superconducting gaps as a unconventional nature. Our findings extend our views and ideas of topological superconductivity in the superconducting heterostructures with time-reversal symmetry breaking, offering an exciting opportunity to elucidate the cooperative effects on the surface state of a topological insulator aligning a superconductor.

Mathematical results on the chiral model of twisted bilayer graphene (with an appendix by Mengxuan Yang and Zhongkai Tao). (arXiv:2310.20642v1 [cond-mat.mes-hall])
Maciej Zworski, Mengxuan Yang, Zhongkai Tao

The study of twisted bilayer graphene (TBG) is a hot topic in condensed matter physics with special focus on {\em magic angles} of twisting at which TBG acquires unusual properties. Mathematically, topologically non-trivial flat bands appear at those special angles. The chiral model of TBG pioneered by Tarnopolsky--Kruchkov--Vishwanath has particularly nice mathematical properties and we survey, and in some cases, clarify, recent rigorous results which exploit them.

Strange Metal to Insulator Transitions in the Lowest Landau Level. (arXiv:2310.20659v1 [cond-mat.str-el])
Ben Currie, Evgeny Kozik

We study the microscopic model of electrons in the partially-filled lowest Landau level interacting via the Coulomb potential by the diagrammatic theory within the GW approximation. In a wide range of filling fractions and temperatures, we find a homogeneous non-Fermi liquid (nFL) state similar to that found in the Sachdev-Ye-Kitaev (SYK) model, with logarithmic corrections to the anomalous dimension. In addition, the phase diagram is qualitatively similiar to that of SYK: a first-order transition terminating at a critical end-point separates the nFL phase from a band insulator that corresponds to the fully-filled Landau level. This critical point, as well as that of the SYK model -- whose critical exponents we determine more precisely -- are shown to both belong to the Van der Waals universality class. The possibility of a charge density wave (CDW) instability is also investigated, and we find the homogeneous nFL state to extend down to the ground state for fillings $0.2 \lesssim \nu \lesssim 0.8$, while a CDW appears outside this range of fillings at sufficiently low temperatures. Our results suggest that the SYK-like nFL state should be a generic feature of the partially-filled lowest Landau level at intermediate temperatures.

Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides. (arXiv:2310.20676v1 [cond-mat.str-el])
Fang Xie, Lei Chen, Qimiao Si

Moir\'e structures, along with line-graph-based $d$-electron systems, represent a setting to realize flat bands. One form of the associated strong correlation physics is the Kondo effect. Here, we address the Kondo-driven heavy fermion state and its destruction in AB-stacked hetero-bilayer transition metal dichalcogenide with tunable filling factor and perpendicular displacement field. In an extended range of the tunable displacement field, the relative filling of the more correlated orbital is enforced to be $\nu_d \approx 1$ by the interaction, which agrees with the experimental observation. We also argue that the qualitative behavior of the crossover associated with the Kondo picture in an extended correlation regime provides the understanding of the energy scales that have been observed in this system. Our results set the stage to address the amplified quantum fluctuations that the Kondo effect may produce in these structures and new regimes that the systems open up for Kondo-destruction quantum criticality.

Intertwined Dirac cones induced by anisotropic coupling in antiferromagnetic topological insulator. (arXiv:2310.20693v1 [cond-mat.mes-hall])
Yiliang Fan, Huaiqiang Wang, Peizhe Tang, Shuichi Murakami, Xiangang Wan, Haijun Zhang, Dingyu Xing

Antiferromagnetic topological insulators (AFM TIs), which host magnetically gapped Dirac-cone surface states and exhibit many exotic physical phenomena, have attracted great attention. The coupling between the top and bottom surface states becomes significant and plays a crucial role in its low-energy physics, as the thickness of an AFM TI film decreases. Here, we find that the coupled surface states can be intertwined to give birth to a set of $2n$ brand new Dirac cones, dubbed \emph{intertwined Dirac cones}, through the anisotropic coupling due to the $n$-fold crystalline rotation symmetry $C_{nz}$ ($n=2, 3, 4, 6$) in the presence of an out-of-plane electric field. Interestingly, we also find that the warping effect further drives the intertwined Dirac-cone state into a quantum anomalous Hall phase with a high Chern number ($C=n$). Then, we demonstrate the emergent six intertwined Dirac cones and the corresponding Chern insulating phase with a high Chern number ($C=3$) in MnBi$_2$Te$_4$$/$(Bi$_2$Te$_3$)$_{\mathrm{m}}/$MnBi$_2$Te$_4$ heterostructures through first-principles calculations. This work discovers a new intertwined Dirac-cone state in AFM TI thin films and also reveals a new mechanism for designing the quantum anomalous Hall state with a high Chern number.

Universal localization-delocalization transition in chirally-symmetric Floquet drives. (arXiv:2310.20696v1 [cond-mat.dis-nn])
Adrian B. Culver, Pratik Sathe, Albert Brown, Fenner Harper, Rahul Roy

Periodically driven systems often exhibit behavior distinct from static systems. In single-particle, static systems, any amount of disorder generically localizes all eigenstates in one dimension. In contrast, we show that in topologically non-trivial, single-particle Floquet loop drives with chiral symmetry in one dimension, a localization-delocalization transition occurs as the time $t$ is varied within the driving period ($0 \le t \le T_\text{drive}$). We find that the time-dependent localization length $L_\text{loc}(t)$ diverges with a universal exponent as $t$ approaches the midpoint of the drive: $L_\text{loc}(t) \sim (t - T_\text{drive}/2)^{-\nu}$ with $\nu=2$. We provide analytical and numerical evidence for the universality of this exponent within the AIII symmetry class.

Topological magnons on the triangular kagome lattice. (arXiv:2207.02886v2 [cond-mat.mes-hall] UPDATED)
Meng-Han Zhang, Dao-Xin Yao

We present the topology of magnons on the triangular kagome lattice (TKL) by calculating its Berry curvature, Chern number and edge states. In addition to the ferromagnetic state, the TKL hosts ferrimagnetic ground state as its two sublattices can couple with each other either ferromagnetically or antiferromagnetically. Using Holstein-Primakoff (HP) boson theory and Green's function approach, we find that the TKL has a rich topological band structure with added high Chern numbers compared with the kagome and honeycomb lattices. The magnon edge current allows a convenient calculation of thermal Hall coefficients and the orbital angular momentum gives correlation to the Einstein-de Haas effect. We apply the calculations to the TKL and derive the topological gyromagnetic ratio showing a nonzero Einstein-de Haas effect in the zero temperature limit. Our results render the TKL as a potential platform for quantum magnonics applications including high-precision mechanical sensors and information transmission.

Weyl excitations via helicon-phonon mixing in conducting materials. (arXiv:2212.08213v3 [cond-mat.mes-hall] UPDATED)
Dmitry K. Efimkin, Sergey Syzranov

Quasiparticles with Weyl dispersion can display an abundance of novel topological, thermodynamic and transport phenomena, which is why novel Weyl materials and platforms for Weyl physics are being intensively looked for in electronic, magnetic, photonic and acoustic systems. We demonstrate that conducting materials in magnetic fields generically host Weyl excitations due to the hybridisation of phonons with helicons, collective neutral modes of electrons interacting with electromagnetic waves propagating in the material. Such Weyl excitations are, in general, created by the interactions of helicons with longitudinal acoustic phonons. An additional type of Weyl excitation in polar crystals comes from the interaction between helicons and longitudinal optical phonons. Such excitations can be detected in X-ray and Raman scattering experiments. The existence of the Weyl excitations involving optical phonons in the bulk of the materials also leads to the formation of topologically protected surface arc states that can be detected via surface plasmon resonance.

Origins of Valley Current Reversal in Partially Overlapped Graphene Layers. (arXiv:2301.10978v2 [cond-mat.mes-hall] UPDATED)
Ryo Tamura

Using the tight-binding model, we investigate the valley current of the `low-bi-up' and `low-bi-low' graphene junction, where `low' and `up' are respectively the lower and upper graphene layers extended from the central AB stacking bilayer graphene layer, `bi'. Source and drain electrodes connect with the left and right monolayer regions, respectively, and thus the total current is forced to flow through the interlayer path in the low-bi-up junction. We measure valley current reversal (VCR) using the average of $\frac{1}{2} \sum_{\nu =\pm}(T_{\nu,-\nu}-T_{\nu,\nu})$ per lateral wave number, where $T_{\nu,\nu'}$ denotes the electron transmission rate from the left $K_{\nu'}$ valley to the right $K_{\nu}$ valley. Without the vertical electric field, the VCR is less than half in both junctions. This VCR is attributed to monolayer--bilayer matching. As the vertical field intensifies, the VCR declines in the low-bi-low junction, but increases to about 0.8 in the low-bi-up junction. This VCR enhancement originates from interlayer matching. Analytic scattering matrixes elucidate these matching effects. Experiments of VCR detection are also proposed.

Non-Fermi Liquids from Dipolar Symmetry Breaking. (arXiv:2304.01181v3 [cond-mat.str-el] UPDATED)
Amogh Anakru, Zhen Bi

The emergence of fractonic topological phases and novel universality classes for quantum dynamics highlights the importance of dipolar symmetry in condensed matter systems. In this work, we study the properties of symmetry-breaking phases of the dipolar symmetries in fermionic models in various spatial dimensions. In such systems, fermions obtain energy dispersion through dipole condensation. Due to the nontrivial commutation between the translation symmetry and dipolar symmetry, the Goldstone modes of the dipolar condensate are strongly coupled to the dispersive fermions and naturally give rise to non-Fermi liquids at low energies. The IR description of the dipolar symmetry-breaking phase is analogous to the well-known theory of a Fermi surface coupled to an emergent U(1) gauge field. We also discuss the crossover behavior when the dipolar symmetry is slightly broken and the cases with anisotropic dipolar conservation.

Rate-equation approach for a charge qudit. (arXiv:2304.04186v2 [cond-mat.mes-hall] UPDATED)
M. P. Liul, A. I. Ryzhov, S. N. Shevchenko

We theoretically describe a driven two-electron four-level double-quantum dot (DQD) tunnel coupled to a fermionic sea by using the rate-equation formalism. This approach allows to find occupation probabilities of each DQD energy level in a relatively simple way, compared to other methods. Calculated dependencies are compared with the experimental results. The system under study is irradiated by a strong driving signal and as a result, one can observe Landau-Zener-Stuckelberg-Majorana (LZSM) interferometry patterns which are successfully described by the considered formalism. The system operation regime depends on the amplitude of the excitation signal and the energy detuning, therefore, one can transfer the system to the necessary quantum state in the most efficient way by setting these parameters. Obtained results give insights about initializing, characterizing, and controlling the quantum system states.

Type-II Dirac points and Dirac nodal loops on the magnons of square-hexagon-octagon lattice. (arXiv:2305.16419v2 [cond-mat.mes-hall] UPDATED)
Meng-Han Zhang, Dao-Xin Yao

We study topological magnons on an anisotropic square-hexagon-octagon (SHO) lattice which has been found by a two-dimensional Biphenylene network (BPN). We propose the concepts of type-II Dirac magnonic states where new schemes to achieve topological magnons are unfolded without requiring the Dzyaloshinsky-Moriya interactions (DMIs). In the ferromagnetic states, the topological distinctions at the type-II Dirac points along with one-dimensional (1D) closed lines of Dirac magnon nodes are characterized by the $\mathbb{Z}_2$ invariant. We find pair annihilation of the Dirac magnons and use the Wilson loop method to depict the topological protection of the band-degeneracy. The Green's function approach is used to calculte chiral edge modes and magnon density of states (DOS). We introduce the DMIs to gap the type-II Dirac magnon points and demonstrate the Dirac nodal loops (DNLs) are robust against the DMIs within a certain parameter range. The topological phase diagram of magnon bands is given via calculating the Berry curvature and Chern number. We find that the anomalous thermal Hall conductivity gives connection to the magnon edge current. Furthermore, we derive the differential gyromagnetic ratio to exhibit the Einstein-de Haas effect (EdH) of magnons with topological features.

Coherence Properties of the Repulsive Anyon-Hubbard Dimer. (arXiv:2306.00073v2 [cond-mat.quant-gas] UPDATED)
Martin Bonkhoff, Simon B. Jäger, Imke Schneider, Axel Pelster, Sebastian Eggert

One-dimensional anyonic models of the Hubbard type show intriguing ground-state properties, effectively transmuting between Bose-Einstein and Fermi-Dirac statistics. The simplest model that one can investigate is an anyonic version of the bosonic Josephson junction, the repulsive anyon-Hubbard dimer. In the following we find an exact duality relation to the Bethe-solvable Bose-Hubbard dimer, which is well known from quantum optics and information theory and has interesting connections to spin squeezing and entangled coherent states. Conversely, we show that the anyonic Hubbard dimer has nontrivial coherence properties that emerge from the anyonic statistics. In particular, we find that coherences can be suppressed and amplified and show that these features are remarkably robust against additional repulsive on-site interactions highlighting the distinct nature of anyons.

Dynamics of electronic states in the insulating Intermediate surface phase of 1T-TaS$_2$. (arXiv:2307.06444v3 [cond-mat.str-el] UPDATED)
Jingwei Dong, Weiyan Qi, Dongbin Shin, Laurent Cario, Zhesheng Chen, Romain Grasset, Davide Boschetto, Mateusz Weis, Pierrick Lample, Ernest Pastor, Tobias Ritschel, Marino Marsi, Amina Taleb, Noejung Park, Angel Rubio, Evangelos Papalazarou, Luca Perfetti

This article reports a comparative study of bulk and surface properties in the transition metal dichalcogenide 1T-TaS$_2$. When heating the sample, the surface displays an intermediate insulating phase that persists for $\sim 10$ K on top of a metallic bulk. The weaker screening of Coulomb repulsion and stiffer Charge Density Wave (CDW) explain such resilience of a correlated insulator in the topmost layers. Both time resolved ARPES and transient reflectivity are employed to investigate the dynamics of electrons and CDW collective motion. It follows that the amplitude mode is always stiffer at the surface and displays variable coupling to the Mott-Peierls band, stronger in the low temperature phase and weaker in the intermediate one.

The distribution of shortest path lengths on trees of a given size in subcritical Erdos-Renyi networks. (arXiv:2310.01591v2 [cond-mat.stat-mech] UPDATED)
Barak Budnick, Ofer Biham, Eytan Katzav

In the subcritical regime Erd\H{o}s-R\'enyi (ER) networks consist of finite tree components, which are non-extensive in the network size. The distribution of shortest path lengths (DSPL) of subcritical ER networks was recently calculated using a topological expansion [E. Katzav, O. Biham and A.K. Hartmann, Phys. Rev. E 98, 012301 (2018)]. The DSPL, which accounts for the distance $\ell$ between any pair of nodes that reside on the same finite tree component, was found to follow a geometric distribution of the form $P(L=\ell | L < \infty) = (1-c) c^{\ell - 1}$, where $0 < c < 1$ is the mean degree of the network. This result includes the contributions of trees of all possible sizes and topologies. Here we calculate the distribution of shortest path lengths $P(L=\ell | S=s)$ between random pairs of nodes that reside on the same tree component of a given size $s$. It is found that $P(L=\ell | S=s) = \frac{\ell+1}{s^{\ell}} \frac{(s-2)!}{(s-\ell-1)!}$. Surprisingly, this distribution does not depend on the mean degree $c$ of the network from which the tree components were extracted. This is due to the fact that the ensemble of tree components of a given size $s$ in subcritical ER networks is sampled uniformly from the set of labeled trees of size $s$ and thus does not depend on $c$. The moments of the DSPL are also calculated. It is found that the mean distance between random pairs of nodes on tree components of size $s$ satisfies ${\mathbb E}[L|S=s] \sim \sqrt{s}$, unlike small-world networks in which the mean distance scales logarithmically with $s$.

Entanglement in BF theory II: Edge-modes. (arXiv:2310.18391v1 [hep-th] CROSS LISTED)
Jackson R. Fliss, Stathis Vitouladitis

We consider the entanglement entropy arising from edge-modes in Abelian $p$-form topological field theories in $d$ dimensions on arbitrary spatial topology and across arbitrary entangling surfaces. We find a series of descending area laws plus universal corrections proportional to the Betti numbers of the entangling surface, which can be taken as a higher-dimensional version of the "topological entanglement entropy." Our calculation comes in two flavors: firstly, through an induced edge-mode theory appearing on the regulated entangling surface in a replica path integral and secondly through a more rigorous definition of the entanglement entropy through an extended Hilbert space. Along the way we establish several key results that are of their own merit. We explain how the edge-mode theory is a novel combination of $(p-1)$-form and $(d-p-2)$-form Maxwell theories linked by a chirality condition, in what we coin a "chiral mixed Maxwell theory." We explicitly evaluate the thermal partition function of this theory. Additionally we show that the extended Hilbert space is completely organized into representations of an infinite-dimensional, centrally extended current algebra which naturally generalizes 2d Kac-Moody algebras to arbitrary dimension and topology. We construct the Verma modules and the representation characters of this algebra. Lastly, we connect the two approaches, showing that the thermal partition function of the chiral mixed Maxwell theory is precisely an extended representation character of our current algebra, establishing an exact correspondence of the edge-mode theory and the entanglement spectrum.

Found 4 papers in prb
Date of feed: Wed, 01 Nov 2023 04:17:02 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)

Rotation-configured topological phase transition in triangle photonic lattices
Chen Chen, Wange Song, Zhiyuan Lin, Shengjie Wu, Shining Zhu, and Tao Li
Author(s): Chen Chen, Wange Song, Zhiyuan Lin, Shengjie Wu, Shining Zhu, and Tao Li

Photonic topological edge states have shown powerful capabilities to manipulate light propagations. In particular, the all-dielectric structures serve as a promising platform to support the topological states, in which the nontrivial photonic band is usually acquired by engineered shape and lattice …

[Phys. Rev. B 108, 134119] Published Tue Oct 31, 2023

Anatomy of spin and current generation from magnetization gradients in topological insulators and Rashba metals
Panagiotis Kotetes, Hano O. M. Sura, and Brian M. Andersen
Author(s): Panagiotis Kotetes, Hano O. M. Sura, and Brian M. Andersen

We explore the spin density and charge currents arising on the surface of a topological insulator and in a two-dimensional Rashba metal due to magnetization gradients. For topological insulators a single interconversion coefficient controls the generation of both quantities. This coefficient is quan…

[Phys. Rev. B 108, 155310] Published Tue Oct 31, 2023

Determination of the spacing between hydrogen-intercalated quasifreestanding monolayer graphene and $6H$-SiC(0001) using total-reflection high-energy positron diffraction
Matthias Dodenhöft, Izumi Mochizuki, Ken Wada, Toshio Hyodo, Peter Richter, Philip Schädlich, Thomas Seyller, and Christoph Hugenschmidt
Author(s): Matthias Dodenhöft, Izumi Mochizuki, Ken Wada, Toshio Hyodo, Peter Richter, Philip Schädlich, Thomas Seyller, and Christoph Hugenschmidt

We have investigated the structure of hydrogen-intercalated quasifreestanding monolayer graphene (QFMLG) grown on $6H$-SiC(0001) by employing total-reflection high-energy positron diffraction. At least nine diffraction spots of the zeroth-order Laue zone were resolved along $〈11\overline{2}0〉$ and t…

[Phys. Rev. B 108, 155438] Published Tue Oct 31, 2023

Tuning the topological character of half-Heusler systems: A comparative study on $\mathrm{Y}T\mathrm{Bi}\phantom{\rule{0.16em}{0ex}}(T=\mathrm{Pd},\phantom{\rule{0.16em}{0ex}}\mathrm{Pt})$
J. C. Souza, M. V. Ale Crivillero, H. Dawczak-Dębicki, Andrzej Ptok, P. G. Pagliuso, and S. Wirth
Author(s): J. C. Souza, M. V. Ale Crivillero, H. Dawczak-Dębicki, Andrzej Ptok, P. G. Pagliuso, and S. Wirth

Half-Heusler systems host a plethora of different ground states, especially with nontrivial topology. However, there is still a lack of spectroscopic insight into the corresponding band inversion in this family. In this work, we locally explore the half-Heuslers $\mathrm{Y}T\mathrm{Bi}$ ($T=\text{Pt…

[Phys. Rev. B 108, 165154] Published Tue Oct 31, 2023

Found 3 papers in prl
Date of feed: Wed, 01 Nov 2023 04:17:06 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)

High-Purity Generation and Switching of Twisted Single Photons
Haoqi Zhao, Yichen Ma, Zihe Gao, Na Liu, Tianwei Wu, Shuang Wu, Xilin Feng, James Hone, Stefan Strauf, and Liang Feng
Author(s): Haoqi Zhao, Yichen Ma, Zihe Gao, Na Liu, Tianwei Wu, Shuang Wu, Xilin Feng, James Hone, Stefan Strauf, and Liang Feng

An experiment combines the two-dimensional semiconductor WSe2 with a spin-orbit-coupled microring resonator to demonstrate the high-purity generation of twisted single photons and its convenient switching between different orbital angular momentum states.

[Phys. Rev. Lett. 131, 183801] Published Tue Oct 31, 2023

Probing a Defect-Site-Specific Electronic Orbital in Graphene with Single-Atom Sensitivity
Mingquan Xu, Aowen Li, Stephen J. Pennycook, Shang-Peng Gao, and Wu Zhou
Author(s): Mingquan Xu, Aowen Li, Stephen J. Pennycook, Shang-Peng Gao, and Wu Zhou

Energy-loss spectroscopy mapping of a silicon point defect in graphene demonstrates real-space mapping of specific electronic excitations at the single-atom scale.

[Phys. Rev. Lett. 131, 186202] Published Tue Oct 31, 2023

Spurious Symmetry Enhancement in Linear Spin Wave Theory and Interaction-Induced Topology in Magnons
Matthias Gohlke, Alberto Corticelli, Roderich Moessner, Paul A. McClarty, and Alexander Mook
Author(s): Matthias Gohlke, Alberto Corticelli, Roderich Moessner, Paul A. McClarty, and Alexander Mook

Linear spin wave theory (LSWT) is the standard technique to compute the spectra of magnetic excitations in quantum materials. In this Letter, we show that LSWT, even under ordinary circumstances, may fail to implement the symmetries of the underlying ordered magnetic Hamiltonian leading to spurious …

[Phys. Rev. Lett. 131, 186702] Published Tue Oct 31, 2023

Found 1 papers in nano-lett
Date of feed: Tue, 31 Oct 2023 13:11:10 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] Converting the Bulk Transition Metal Dichalcogenides Crystal into Stacked Monolayers via Ethylenediamine Intercalation
Yeojin Ahn, Gyubin Lee, Namgyu Noh, Chulwan Lee, Duc Duy Le, Sunghun Kim, Yeonghoon Lee, Jounghoon Hyun, Chan-young Lim, Jaehun Cha, Mingi Jho, Seonggeon Gim, Jonathan D. Denlinger, Chan-Ho Yang, Jong Min Yuk, Myung Joon Han, and Yeongkwan Kim

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.3c02268

Found 4 papers in acs-nano
Date of feed: Tue, 31 Oct 2023 13:07:00 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] Chalcogen and Pnictogen Bonding-Modulated Multiple-Constituent Chiral Self-Assemblies
Yiran Xia, Aiyou Hao, and Pengyao Xing

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c08590

[ASAP] Challenging Prevalent Solid Electrolyte Interphase (SEI) Models: An Atom Probe Tomography Study on a Commercial Graphite Electrode
Isabel Pantenburg, Marvin Cronau, Torben Boll, Annalena Duncker, and Bernhard Roling

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c06560

[ASAP] Nanoporous MoS2 Field-Effect Transistor Based Artificial Olfaction: Achieving Enhanced Volatile Organic Compound Detection Inspired by the Drosophila Olfactory System
Junoh Shim, Anamika Sen, Keehyun Park, Heekyeong Park, Arindam Bala, Hyungjun Choi, Mincheol Park, Jae Young Kwon, and Sunkook Kim

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c07045

[ASAP] Differing Electrolyte Implication on Anion and Cation Intercalation into Graphite
Yaqi He, Cheng Zhen, Menghao Li, Xianbin Wei, Cheng Li, Yuanmin Zhu, Xuming Yang, and M. Danny Gu

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c07053

Found 2 papers in nat-comm

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)

Gate-controlled suppression of light-driven proton transport through graphene electrodes
< author missing >

Graphene/silicon heterojunction for reconfigurable phase-relevant activation function in coherent optical neural networks
< author missing >

Found 1 papers in scipost

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)

Dipole symmetries from the topology of the phase space and the constraints on the low-energy spectrum, by Tomas Brauner, Naoki Yamamoto, Ryo Yokokura
< author missing >
Submitted on 2023-10-31, refereeing deadline 2023-12-06.