Found 34 papers in cond-mat
Date of feed: Fri, 15 Sep 2023 00:30:00 GMT

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Topological superconductivity mediated by magnons of helical magnetic states. (arXiv:2309.07211v1 [cond-mat.supr-con])
Kristian Mæland, Sara Abnar, Jacob Benestad, Asle Sudbø

We recently showed that spin fluctuations of noncoplanar magnetic states can induce topological superconductivity in an adjacent normal metal [K. M{\ae}land et al., Phys. Rev. Lett. 130, 156002 (2023)]. The noncolinear nature of the spins was found to be essential for this result, while the necessity of noncoplanar spins was unclear. In this paper we show that magnons in coplanar, noncolinear magnetic states can mediate topological superconductivity in a normal metal. Two models of the Dzyaloshinskii-Moriya interaction are studied to illustrate the need for a sufficiently complicated Hamiltonian describing the magnetic insulator. The Hamiltonian, in particular the specific form of the Dzyaloshinskii-Moriya interaction, affects the magnons and by extension the effective electron-electron interaction in the normal metal. We solve a linearized gap equation in the case of weak-coupling superconductivity. The result is a time-reversal-symmetric topological superconductor, as confirmed by calculating the topological invariant. In analogy with magnon-mediated superconductivity from antiferromagnets, Umklapp scattering enhances the critical temperature of superconductivity for certain Fermi momenta.

Spin-valley entangled quantum Hall states in graphene. (arXiv:2309.07217v1 [cond-mat.mes-hall])
Nikolaos Stefanidis, Inti Sodemann Villadiego

We investigate interaction-driven integer quantum Hall states realized in Landau levels of monolayer graphene when two out of its four nearly degenerate spin-valley flavors are filled. By employing a model that accounts for interactions beyond pure delta-functions as well as Zeeman and substrate-induced valley potentials, we demonstrate the existence of a delicate competition of several phases with spontaneous generation of spin-valley entanglement, akin to the spontaneous appearance of spin-orbit coupling driven by interactions. We encounter a particular phase that we term the entangled-Kekul\'{e}-antiferromagnet (E-KD-AF) which only becomes spin-valley entangled under the simultaneous presence of Zeeman and substrate potentials, because it gains energy by simultaneously canting in the spin and valley spaces, by combining features of a canted anti-ferromagnet and a canted Kekul\'{e} state. We quantify the degree of spin-valley entanglement of the many competing phases by computing their bipartite concurrence.

Time-Reversal Invariant Topological Moir\'e Flatband: A Platform for the Fractional Quantum Spin Hall Effect. (arXiv:2309.07222v1 [cond-mat.mes-hall])
Yi-Ming Wu, Daniel Shaffer, Zhengzhi Wu, Luiz H. Santos

Motivated by recent experimental observation of the quantum spin Hall effect in monolayer germanene, we study the topological phases of twisted bilayer Kane-Mele model with time-reversal symmetry and spin $s_z$ conservation. For large twist angles the helical edge states from the two layers are unstable and the system is a trivial insulator. At small twist angles however, the emergent moir\'e flatbands can be topologically nontrivial due to inversion symmetry breaking from coupling to substrate. Each of these flatbands for each spin projection admits a lowest-Landau-level description in the chiral limit and at magic twist angle. This allows for the construction of a many-body Laughlin state with time-reversal symmetry which can be stabilized by a short-range pseudopotential, and therefore serves as an ideal platform for realizing the so-far elusive fractional quantum spin Hall effect with emergent spin-1/2 U(1) symmetry.

Self-duality properties and localization centers of the electronic wave functions at high magic angles in twisted bilayer graphene. (arXiv:2309.07260v1 [cond-mat.mes-hall])
Leonardo A. Navarro-Labastida, Gerardo G. Naumis

Twisted bilayer graphene (TBG) is known for exhibiting highly correlated phases at magic angles due to the emergence of flat bands that enhance electron-electron interactions. In the TBG chiral model, electronic wave function properties depend on a single parameter ($\alpha$), inversely proportional to the relative twist angle between the two graphene layers. In previous studies, as the twist angles approached small values, strong confinement, and convergence to coherent Landau states were observed. This work explores flat-band electronic modes, revealing that flat band states exhibit self-duality; they are coherent Landau states in reciprocal space and exhibit minimal dispersion, with standard deviation $\sigma_k=\sqrt{3\alpha/2\pi}$ as $\alpha$ approaches infinity. Subsequently, by symmetrizing the wave functions and considering the squared TBG Hamiltonian, the strong confinement observed in the $\alpha\rightarrow\infty$ limit is explained. This confinement arises from the combination of the symmetrized squared norm of the moir\'e potential and the quantized orbital motion of electrons, effectively creating a quantum well. The ground state of this well, located at defined spots, corresponds to Landau levels with energy determined by the magic angle. Furthermore, we demonstrate that the problem is physically analogous to an electron attached to a non-Abelian $SU(2)$ gauge field with an underlying $C_3$ symmetry. In regions of strong confinement, the system can be considered as Abelian. This allows to define a magnetic energy in which the important role of the wave function parity and gap closing at non-magic angles is revealed. Finally, we investigate the transition from the original non-Abelian nature to an Abelian state by artificially changing the pseudo-magnetic vector components from an $SU(2)$ to a $U(1)$ field, which alters the sequence of magic angles.

Topological protection of Majorana polaritons in a cavity. (arXiv:2309.07278v1 [cond-mat.mes-hall])
Zeno Bacciconi, Gian Marcello Andolina, Christophe Mora

Cavity embedding is an emerging paradigm for the control of quantum matter, offering avenues to manipulate electronic states and potentially drive topological phase transitions. In this work, we address the stability of a one-dimensional topological superconducting phase to the vacuum quantum fluctuations brought by a global cavity mode. By employing a quasi-adiabatic analytical approach completed by density matrix renormalization group calculations, we show that the Majorana end modes evolve into composite polaritonic modes while maintaining the topological order intact and robust to disorder. These Majorana polaritons keep their non-abelian exchange properties and protect a twofold exponentially degenerate ground state for an open chain.

A mechanically-derived contact model for adhesive elastic-perfectly plastic particles. Part I: Utilizing the method of dimensionality reduction. (arXiv:2309.07300v1 [cond-mat.soft])
William Zunker, Ken Kamrin

In this two part series, we present a contact model able to capture the response of interacting adhesive elastic-perfectly plastic particles under a variety of loadings. In Part I, we focus on elastic through fully-plastic contact with and without adhesion. For these contact regimes the model is built upon the method of dimensionality reduction which allows the problem of a 3D axisymmetric contact to be mapped to a semi-equivalent problem of a 1D rigid indenter penetrating a bed of independent Hookean springs. Plasticity is accounted for by continuously varying the 1D indenter profile subject to a constraint on the contact pressure. Unloading falls out naturally, and simply requires lifting the 1D indenter out of the springs and tracking the force. By accounting for the incompressible nature of this plastic deformation, the contact model is able to capture multi-neighbor dependent effects such as increased force and formation of new contacts. JKR type adhesion is recovered seamlessly within the method of dimensionality reduction by simply allowing the springs to stick to the 1D indenter's surface. Because of the mechanics-focused formulation of the contact model, only a few physical inputs describing the interacting particles are needed: particle radius, Young's modulus, Poisson ratio, yield stress, and effective surface energy. The contact model is validated against finite element simulations and analytic theory, including Hertz's contact law and the JKR theory of adhesion. These comparisons show that the proposed contact model is able to accurately capture plastic displacement, average contact pressure, contact area, and force as a function of displacement for contacts as well as particle volume within the elastic to fully-plastic regimes.

Bicrystallography-informed Frenkel-Kontorova model for interlayer dislocations in strained 2D heterostructures. (arXiv:2309.07325v1 [cond-mat.mes-hall])
Md Tusher Ahmed, Chenhaoyue Wang, Amartya S. Banerjee, Nikhil Chandra Admal

In recent years, van der Waals (vdW) heterostructures and homostructures, which consist of stacks of two-dimensional (2D) materials, have risen to prominence due to their association with exotic quantum phenomena. Atomistic scale relaxation effects play an extremely important role in the electronic scale quantum physics of these systems. We investigate such structural relaxation effects in this work using atomistic and mesoscale models, within the context of twisted bilayer graphene -- a well-known heterostructure system that features moire patterns arising from the lattices of the two graphene layers. For small twist angles, atomic relaxation effects in this system are associated with the natural emergence of interface dislocations or strain solitons, which result from the cyclic nature of the generalized stacking fault energy (GSFE), that measures the interface energy based on the relative movement of the two layers. In this work, we first demonstrate using atomistic simulations that atomic reconstruction in bilayer graphene under a large twist also results from interface dislocations, although the Burgers vectors of such dislocations are considerably smaller than those observed in small-twist systems. To reveal the translational invariance of the heterointerface responsible for the formation of such dislocations, we derive the translational symmetry of the GSFE of a 2D heterostructure using the notions of coincident site lattices (CSLs) and displacement shift complete lattices (DSCLs). The workhorse for this exercise is a recently developed Smith normal form bicrystallography framework. Next, we construct a bicrystallography-informed and frame-invariant Frenkel-Kontorova model, which can predict the formation of strain solitons in arbitrary 2D heterostructures, and apply it to study a heterostrained, large-twist bilayer graphene system.

Electronic and spin transport in Bismuthene with magnetic impurities. (arXiv:2309.07328v1 [cond-mat.mes-hall])
Armando Pezo, Felipe Crasto de Lima, Adalberto Fazzio

Topological insulators have remained as candidates for future electronic devices since their first experimental realization in the past decade. The existence of topologically protected edge states could be exploited to generate a robust platform and develop quantum computers. In this work we explore the role of magnetic impurities in the transport properties of topological insulators, in particular, we study the effect on the edge states conductivity. By means of realistic $\it{ab}$ $\it{initio}$ calculations we simulate the interaction between magnetic adatoms and topological insulators, furthermore, our main goal is to obtain the transport properties for large samples as it would be possible to localize edge states at large scales.

Intercalation in 2H-TaSe 2 for modulation of electronic properties and electrochemical energy storage. (arXiv:2309.07543v1 [cond-mat.str-el])
S. Koley

Two-dimensional transition metal dichalcogenides (TMDs) exhibit an extensive variety of novel electronic properties, such as charge density wave quantum spin Hall phenomena, superconductivity, and Dirac and Weyl semi-metallic properties. The diverse properties of TMDs suggest that structural transformation can be employed to switch between different electronic properties. Intercalation and zero valence doping of molecules and atoms into the van der Waals gap of TMDs have emerged as effective approaches to modify the charge order states of the material. This eventually leads to phase transition or the formation of different phases, thus expanding the electronic, thermoelectric and optical applications of these materials. In this study, electronic and electrochemical energy storage properties of such an intercalated TMD, namely, 2H-TaSe 2 via intercalation of lithium (Li), sodium (Na) and potassium (K) have been investigated. The intercalation of these ions into the dichalcogenide resulted in a modified band structure and novel structural effects, leading to the emergence of a 1 eV band gap. Possibility of electrochemical energy storage application is also explored in this study. Furthermore, the importance of multi orbital electron-electron correlations in intercalated TaSe 2 is also investigated via dynamical-mean-field theory with local density approximation.

Persistence in Active Turbulence. (arXiv:2309.07567v1 [physics.flu-dyn])
Amal Manoharan, Sanjay CP, Ashwin Joy

Active fluids such as bacterial swarms, self-propelled colloids, and cell tissues can all display complex spatio-temporal vortices that are reminiscent of inertial turbulence. This emergent behavior despite the overdamped nature of these systems is the hallmark of active turbulence. In this letter, using a generalized hydrodynamic model, we present a study of the persistence problem in active turbulence. We report that the persistence time of passive tracers inside the coherent vortices follows a Weibull probability density whose shape and scale are decided by the strength of activity -- contrary to inertial turbulence that displays power-law statistics in this region. In the turbulent background, the persistence time is exponentially distributed that is remindful of inertial turbulence. Finally we show that the driver of persistence inside the coherent vortices is the temporal decorrelation of the topological field, whereas it is the vortex turnover time in the turbulent background.

Spin-Selective Electron Transport Through Single Chiral Molecules. (arXiv:2309.07588v1 [cond-mat.mes-hall])
Mohammad Reza Safari, Frank Matthes, Claus M. Schneider, Karl-Heinz Ernst, Daniel E. Bürgler

The interplay between chirality and magnetism has been a source of fascination among scientists for over a century. In recent years, chirality-induced spin selectivity (CISS) has attracted renewed interest. It has been observed that electron transport through layers of homochiral molecules leads to a significant spin polarization of several tens of percent. Despite the abundant experimental evidence gathered through mesoscopic transport measurements, the exact mechanism behind CISS remains elusive. In this study, we report spin-selective electron transport through single helical aromatic hydrocarbons that were sublimed in vacuo onto ferromagnetic cobalt surfaces and examined with spin-polarized scanning tunneling microscopy (SP-STM) at a temperature of 5 K. Direct comparison of two enantiomers under otherwise identical conditions revealed magnetochiral conductance asymmetries of up to 50% when either the molecular handedness was exchanged or the magnetization direction of the STM tip or Co substrate was reversed. Importantly, our results rule out electron-phonon coupling and ensemble effects as primary mechanisms responsible for CISS.

Transmission in graphene through a double laser barrier. (arXiv:2309.07591v1 [cond-mat.mes-hall])
Rachid El Aitouni, Miloud Mekkaoui, Ahmed Jellal

In this work, we will study the transmission probability of Dirac fermions through a double laser barrier. As part of the Floquet approximation, we will determine the spinors in the five regions. Due to the continuity of the wave function at the barrier edges, we find eight equations, each with infinity modes. To simplify, we use the matrix formalism and limit our study to the first three bands, the central band, and the first two side bands. From the continuity equation and the spinors in the five regions, we will determine the current density in each region, which makes it possible to determine the expression of the transmission probability corresponding to each energy band. The time-dependent laser fields generate several transmission modes, which give two transmission processes: transmission with zero photon exchange corresponds to the central band $\varepsilon$, and transmission with emission or absorption of photons corresponds to the first two sidebands $\varepsilon\pm\varpi$. One of the two modes can be suppressed by varying the distance between the two barriers or the barrier width. The transmission is not permitted if the incoming energy is below an energy threshold $\varepsilon>k_y+2\varpi$. Increasing the intensity of the laser fields makes it possible to modify the sharpness and amplitude of the transmission.

Enhanced Non-linear Response by Manipulating the Dirac Point in the (111) LaTiO$_3$/SrTiO$_3$ Interface. (arXiv:2309.07706v1 [cond-mat.str-el])
G. Tuvia, A. Burshtein, I. Silber, A. Aharony, O. Entin-Wohlman, M. Goldstein, Y. Dagan

Tunable spin-orbit interaction (SOI) is an important feature for future spin-based devices. In the presence of a magnetic field, SOI induces an asymmetry in the energy bands, which can produce non-linear transport effects ($V\sim I^2$). Here, we focus on such effects to study the role of SOI in the (111) LaTiO$_3$/SrTiO$_3$ interface. This system is a convenient platform for understanding the role of SOI since it exhibits a single-band Hall-response through the entire gate-voltage range studied. We report a pronounced rise in the non-linear resistance at a critical in-plane field $H_{cr}$. This rise disappears with a small out-of-plane field. We explain these results by considering the location of the Dirac point formed at the crossing of the spin-split energy bands. An in-plane magnetic field pushes this point outside of the Fermi surface, and consequently changes the symmetry of the Fermi contours and intensifies the non-linear transport. An out-of-plane magnetic field opens a gap at the Dirac point, thereby significantly diminishing the non-linear effects. We propose that magnetoresistance effects previously reported in interfaces with SOI could be comprehended within our suggested scenario.

Tolerance and breakdown of topological protection in a disordered waveguide. (arXiv:2309.07710v1 [cond-mat.dis-nn])
Kiyanoush Goudarzi, Moonjoo Lee

We consider a disordered waveguide consisting of trivial dielectric and non-trivial magnetically anisotropic material. A topologically-protected edge mode appears owing to the broken time-reversal symmetry of the non-trivial lattice. While the edge mode maintains under other position and radius disorders, the protection is immediately broken by applying a radius disorder to the non-trivial lattice. This breakdown originates from donor and acceptor modes occupying the topological bandgap. Furthermore, via the calculation of the Bott index, we show that Anderson localization occurs as a metal conducting gap changes to a topological gap along with increasing disorders.

Eleven Competing Phases in the Heisenberg-Gamma (J$\Gamma$) Ladder. (arXiv:2309.07737v1 [cond-mat.str-el])
Sebastien J. Avakian, Erik S. Sørensen

The spin-orbit generated $\Gamma$ interaction is known to induce strong frustration and to be significant in realistic models of materials. To gain an understanding of the possible phases that can arise from this interaction, it is of considerable interest to focus on a limited part of parameter space in a quasi one-dimensional model where high precision numerical results can be obtained. Here we study the Heisenberg-Gamma (J$\Gamma$) ladder, determining the complete zero temperature phase diagram by analyzing the entanglement spectrum (ES) and energy susceptibility. A total of 11 different phases can be identified. Two of the phases, the antiferromagnetic Gamma (A$\Gamma$) and ferromagnetic Gamma (F$\Gamma$) phases, have previously been observed in the Kitaev-Gamma ladder, demonstrating that the A$\Gamma$-phase is a symmetry protected topological phase (SPT) protected by $TR\times \mathcal{R}_{b}$ symmetry, the product of time-reversal ($TR$) and $\pi$ rotation around the $b$-axis ($\mathcal{R}_{b}$), while the F$\Gamma$-phase is related to a rung-singlet phase through a local unitary transformation. Three other phases, $\Upsilon$, $\Omega$ and $\delta$ show no conventional order, a doubling of the entanglement spectrum and for the $\Upsilon$ and $\Omega$-phases a gap is clearly present. The $\delta$-phase has a significantly smaller gap and displays incommensurate correlations, with a peak in the static structure factor, $S(k)$ continuously shifting from $k/\pi\mathord{=}2/3$ to $k\mathord{=}\pi$. In the $\Omega$-phase we find pronounced edge-states consistent with a SPT phase protected by the same $TR\times \mathcal{R}_{b}$ symmetry as the A$\Gamma$-phase. The precise nature of the $\Upsilon$ and $\delta$-phases is less clear.

Klein-bottle quadrupole insulators and Dirac semimetals. (arXiv:2309.07784v1 [cond-mat.mes-hall])
Chang-An Li, Junsong Sun, Song-Bo Zhang, Huaiming Guo, Björn Trauzettel

The Benalcazar-Bernevig-Hughes (BBH) quadrupole insulator model is a cornerstone model for higher-order topological phases. It requires \pi flux threading through each plaquette of the two-dimensional Su-Schrieffer-Heeger model. Recent studies show that particular \pi-flux patterns can modify the fundamental Brillouin zone from the shape of a torus to a Klein-bottle with emerging topological phases. By designing different \pi-flux patterns, we propose two types of Klein-bottle BBH models. These models show rich topological phases including Klein-bottle quadrupole insulators and Dirac semimetals. The phase with nontrivial Klein-bottle topology shows twined edge modes at open boundaries. These edge modes can further support second-order topology yielding a quadrupole insulator. Remarkably, both models are robust against flux perturbations. Moreover, we show that different \pi-flux patterns dramatically affect the phase diagram of the Klein-bottle BBH models. Going beyond the original BBH model, Dirac semimetal phases emerge in Klein-bottle BBH models featured by the coexistence of twined edge modes and bulk Dirac points.

Predicting the mechanical properties of spring networks. (arXiv:2309.07844v1 [cond-mat.soft])
Doron Grossman, Arezki Boudaoud

The elastic response of mechanical, chemical, and biological systems is often modeled using a discrete arrangement of Hookean springs, either modeling finite material elements or even the molecular bonds of a system. However, to date, there is no direct derivation of the relation between discrete spring network, and a general elastic continuum. Furthermore, understanding the networks' mechanical response requires simulations that may be expensive computationally. Here we report a method to derive the exact elastic continuum model of any discrete network of springs, requiring network geometry and topology only. We identify and calculate the so-called "non-affine" displacements. Explicit comparison of our calculations to simulations of different crystalline and disordered configurations, shows we successfully capture the mechanics even of auxetic materials. Our method is valid for residually stressed systems with non-trivial geometries, is easily generalizable to other discrete models, and opens the possibility of a rational design of elastic systems.

The mass of simple and higher-order networks. (arXiv:2309.07851v1 [cond-mat.dis-nn])
Ginestra Bianconi

We propose a theoretical framework that explains how the mass of simple and higher-order networks emergences from their topology and their geometry. We use the discrete topological Dirac operator to define an action for a massless self-interacting topological Dirac field inspired by the Nambu-Jona Lasinio model.The mass of the network is the result of the chiral symmetry breaking and satisfies a self-consistent gap equation. Interestingly it is shown that the mass of a network depends on its spectral properties, topology and geometry. Due to the breaking of the matter-antimatter symmetry observed for the harmonic modes of the discrete topological Dirac operator, two possible definitions of the network mass can be given. For both possible definitions, the mass of the network comes from a gap equation with the difference among the two definitions encoded in the value of the bare mass. Indeed the bare mass can be determined either by the Betti number $\beta_0$ or by the Betti number $\beta_1$ of the network.We provide numerical results on the mass of different networks, including random graphs, scale-free and real weighted collaboration networks. We discuss also the generalization of these results to higher-order networks defining the mass of simplicial complexes.

Water, not salt, causes most of the Seebeck effect of nonisothermal aqueous electrolytes. (arXiv:2309.07853v1 [physics.chem-ph])
Ole Nickel, Ludwig J. V. Ahrens-Iwers, Robert H. Meißner, Mathijs Janssen

When two electrolyte-immersed electrodes have different temperatures, a voltage $\Delta \psi$ can be measured between them. This electrolyte Seebeck effect is usually explained by cations and anions flowing differently in thermal gradients. However, our molecular dynamics simulations of aqueous electrolytes reveal a large temperature-dependent potential drop $\chi$ near blocking electrodes caused by water layering and orientation. The difference in surface potentials at hot and cold electrodes is more important to the Seebeck effect than ionic thermodiffusion, $\Delta \psi \sim \chi_{\rm hot}-\chi_{\rm cold}$.

Particle-hole asymmetric ferromagnetism and spin textures in the triangular Hubbard-Hofstadter model. (arXiv:2309.07876v1 [cond-mat.str-el])
Jixun K. Ding, Luhang Yang, Wen O. Wang, Ziyan Zhu, Cheng Peng, Peizhi Mai, Edwin W. Huang, Brian Moritz, Phillip W. Phillips, Benjamin E. Feldman, Thomas P. Devereaux

In a lattice model subject to a perpendicular magnetic field, when the lattice constant is comparable to the magnetic length, one enters the "Hofstadter regime," where continuum Landau levels become fractal magnetic Bloch bands. Strong mixing between bands alters the nature of the resulting quantum phases compared to the continuum limit; lattice potential, magnetic field, and Coulomb interaction must be treated on equal footing. Using determinant quantum Monte Carlo (DQMC) and density matrix renormalization group (DMRG) techniques, we study this regime numerically in the context of the Hubbard-Hofstadter model on a triangular lattice. In the field-filling phase diagram, we find a broad wedge-shaped region of ferromagnetic ground states for filling factor $\nu \lesssim 1$, bounded by incompressible states at filling factor $\nu = 1$. For magnetic field strengths $\Phi/\Phi_0 \lesssim 0.4$, we observe signatures of SU(2) quantum Hall ferromagnetism in the lowest magnetic Bloch band; however, we find no numerical evidence for conventional quantum Hall skyrmions. At large fields $\Phi/\Phi_0 \gtrsim 0.4$, above the ferromagnetic wedge, we observe a low-spin metallic region with spin correlations peaked at small momenta. We argue that the phenomenology of this region likely results from exchange interaction mixing fractal Hofstadter subbands. The phase diagram derived beyond the continuum limit points to a rich landscape to explore interaction effects in magnetic Bloch bands.

Vortex Lattices in Active Nematics with Periodic Obstacle Arrays. (arXiv:2309.07886v1 [cond-mat.soft])
Cody D. Schimming, C. J. O. Reichhardt, C. Reichhardt

We numerically model a two-dimensional active nematic confined by a periodic array of fixed obstacles. Even in the passive nematic, the appearance of topological defects is unavoidable due to planar anchoring by the obstacle surfaces. We show that a vortex lattice state emerges as activity is increased, and that this lattice may be tuned from ``ferromagnetic'' to ``antiferromagnetic'' by varying the gap size between obstacles. We map the rich variety of states exhibited by the system as a function of distance between obstacles and activity, including a pinned defect state, motile defects, the vortex lattice, and active turbulence. We demonstrate that the flows in the active turbulent phase can be tuned by the presence of obstacles, and explore the effects of a frustrated lattice geometry on the vortex lattice phase.

Collective non-Hermitian skin effect: Point-gap topology and the doublon-holon excitations in non-reciprocal many-body systems. (arXiv:2309.07894v1 [cond-mat.str-el])
Beom Hyun Kim, Jae-Ho Han, Moon Jip Park

Open quantum systems provide a plethora of exotic topological phases of matter that has no Hermitian counterpart. Non-Hermitian skin effect, macroscopic collapse of bulk states to the boundary, has been extensively studied in various experimental platforms. However, it remains an open question whether such topological phases persist in the presence of many-body interactions. Notably, previous studies have shown that the Pauli exclusion principle suppresses the skin effect. In this study, we present a compelling counterexample by demonstrating the presence of the skin effect in doublon-holon excitations. While the ground state of the spin-half Hatano-Nelson model shows no skin effect, the doublon-holon pairs, as its collective excitations, display the many-body skin effect even in strong coupling limit. We rigorously establish the robustness of this effect by revealing a bulk-boundary correspondence mediated by the point gap topology within the many-body energy spectrum. Our findings underscore the existence of non-Hermitian topological phases in collective excitations of many-body interacting systems.

Quantum Electrodynamics of Non-Hermitian Dirac Fermions. (arXiv:2309.07916v1 [cond-mat.str-el])
Sk Asrap Murshed, Bitan Roy

We develop an effective quantum electrodynamics for non-Hermitian (NH) Dirac materials interacting with photons. These systems are described by Lorentz invariant NH Dirac operators, featuring two velocity parameters $v_{_{\rm H}}$ and $v_{_{\rm NH}}$ associated with the standard Hermitian and a masslike anti-Hermitian Dirac operators, respectively. They display linear energy-momentum relation, however, in terms of an effective Fermi velocity $v_{_{\rm F}}=\sqrt{v^2_{_{\rm H}}-v^2_{_{\rm NH}}}$ of NH Dirac fermions. Interaction with the fluctuating electromagnetic radiation then gives birth to an emergent Lorentz symmetry in this family of NH Dirac materials in the deep infrared regime, where the system possesses a unique terminal velocity $v_{_{\rm F}}=c$, with $c$ being the speed of light. While in two dimensions such a terminal velocity is set by the speed of light in the free space, dynamic screening in three spatial dimensions permits its nonuniversal values. Manifestations of such an emergent spacetime symmetry on the scale dependence of various physical observables in correlated NH Dirac materials are discussed.

Intrinsic non-magnetic $\phi_0$ Josephson junctions in twisted bilayer graphene. (arXiv:2303.07738v2 [cond-mat.mes-hall] UPDATED)
Miguel Alvarado, Pablo Burset, Alfredo Levy Yeyati

Recent experiments have demonstrated the possibility to design highly controllable junctions on magic angle twisted bilayer graphene, enabling the test of its superconducting transport properties. We show that the presence of chiral pairing in such devices manifests in the appearance of an anomalous Josephson effect ($\phi_0$ behavior) even in the case of symmetric junctions and without requiring any magnetic materials or fields. Such behavior arises from the combination of chiral pairing and nontrivial topology of the twisted bilayer graphene band structure that can effectively break inversion symmetry. Moreover, we show that the $\phi_0$ effect could be experimentally enhanced and controlled by electrostatic tuning of the junction transmission properties.

Mixed-state long-range order and criticality from measurement and feedback. (arXiv:2303.15507v2 [cond-mat.str-el] UPDATED)
Tsung-Cheng Lu, Zhehao Zhang, Sagar Vijay, Timothy H. Hsieh

We propose a general framework for using local measurements, local unitaries, and non-local classical communication to construct quantum channels which can efficiently prepare mixed states with long-range quantum order or quantum criticality. As an illustration, symmetry-protected topological (SPT) phases can be universally converted into mixed-states with long-range entanglement, which can undergo phase transitions with quantum critical correlations of local operators and a logarithmic scaling of the entanglement negativity, despite coexisting with volume-law entropy. Within the same framework, we present two applications using fermion occupation number measurement to convert (i) spinful free fermions in one dimension into a quantum-critical mixed state with enhanced algebraic correlations between spins and (ii) Chern insulators into a mixed state with critical quantum correlations in the bulk. The latter is an example where mixed-state quantum criticality can emerge from a gapped state of matter in constant depth using local quantum operations and non-local classical communication.

Topological Circular Dichroism in Chiral Multifold Semimetals. (arXiv:2303.17553v2 [cond-mat.mes-hall] UPDATED)
Junyeong Ahn, Barun Ghosh

Uncovering the physical contents of the nontrivial topology of quantum states is a critical problem in condensed matter physics. Here, we study the topological circular dichroism in chiral semimetals using linear response theory and first-principles calculations. We show that, when the low-energy spectrum respects emergent SO(3) rotational symmetry, topological circular dichroism is forbidden for Weyl fermions, and thus is unique to chiral multifold fermions. This is a result of the selection rule that is imposed by the emergent symmetry under the combination of particle-hole conjugation and spatial inversion. Using first-principles calculations, we predict that topological circular dichroism occurs in CoSi for photon energy below about 0.2 eV. Our work demonstrates the existence of a response property of unconventional fermions that is fundamentally different from the response of Dirac and Weyl fermions, motivating further study to uncover other unique responses.

Effect of magnetic field on the electronic properties of an $\alpha$-$T_3$ ring. (arXiv:2304.08830v2 [cond-mat.mes-hall] UPDATED)
Mijanur Islam, Tutul Biswas, Saurabh Basu

We consider a quantum ring of a certain radius R built from a sheet of the $\alpha$-$T_3$ lattice and solve for its spectral properties in presence of an external magnetic field. The energy spectrum consists of a conduction band, a valence band and a zero energy flat band, all having a number of discrete levels therein which can be characterized by the angular momentum quantum number, m. The energy levels in the flat band are infinitely degenerate irrespective of the value of $\alpha$. We reveal a two-fold degeneracy of the levels in the conduction band as well as in the valence band for $\alpha$ = 0 and $\alpha$ = 1. However, the m = 0 level for $\alpha$ = 1 is an exception. Corresponding to an intermediate value of $\alpha$, namely, 0 <$\alpha$< 1, the energy levels become nondegenerate. The scenario remains unaltered when the ring is threaded by a magnetic flux which is an integer multiple of the flux quantum. We also calculate the persistent current which exhibits quantum oscillations as a function of the magnetic field with a period of one flux quantum at a particular Dirac point, which is often referred to as a valley. The total current oscillates with a periodicity of one flux quantum for any intermediate value of $\alpha$. We have also explored the effect of a mass term (that breaks the sublattice symmetry) in the Hamiltonian. In the absence of a magnetic field, the energy levels in the flat band become dispersive, except for the m = 0 level in the case of $\alpha$ = 1. In presence of the field, each of the flat band levels becomes dispersive for any $\alpha \neq$ 0. Finally, we also see the effect of the mass term on the behaviour of the persistent current, which shows periodicity of one flux quantum, but the total current remains finite for all values of $\alpha$.

Molecular Beam Epitaxy Growth of Transition Metal Dichalcogenide (Mo,Mn)Se$_2$ on 2D, 3D and polycrystalline substrates. (arXiv:2304.12428v2 [cond-mat.mtrl-sci] UPDATED)
Julia Kucharek, Rafał Bożek, Wojciech Pacuski

Magnetic doping of 2D materials such as Transition Metal Dichalcogenides is promising for the enhancement of magneto-optical properties, as it was previously observed for 3D diluted magnetic semiconductors. To maximize the effect of magnetic ions, they should be incorporated into the crystal lattice of 2D material rather than form separated precipitates. This work shows a study on incorporating magnetic manganese ions into the MoSe$_2$ monolayers using molecular beam epitaxy. We test growth on various substrates with very different properties: polycrystalline SiO$_2$ on Si, exfoliated 2D hexagonal Boron Nitride flakes (placed on SiO$_2$ / Si), monocrystalline sapphire, and exfoliated graphite (on tantalum foil). Although atomic force microscopy images indicate the presence of MnSe precipitates, but at the same time, various techniques reveal effects related to alloying MoSe$_2$ with Mn: Raman scattering and photoluminescence measurements show energy shift related to the presence of Mn, scanning transmission microscopy shows Mn induced partial transformation of 1H to 1T^\prime phase. Above effects evidence partial incorporation of Mn into the MoSe$_2$ layer.

Long-range correlation-induced effects at high-order harmonic generation on graphene quantum dots. (arXiv:2305.14034v2 [cond-mat.mes-hall] UPDATED)
H.K. Avetissian, A.G. Ghazaryan, Kh.V. Sedrakian, G.F. Mkrtchian

This paper focuses on investigating high-order harmonic generation (HHG) in graphene quantum dots (GQDs) under intense near-infrared laser fields. To model the GQD and its interaction with the laser field, we utilize a mean-field approach. Our analysis of the HHG power spectrum reveals fine structures and a noticeable enhancement in cutoff harmonics due to the long-range correlations. We also demonstrate the essential role of Coulomb interaction in determining of harmonics intensities and cutoff position. Unlike atomic HHG, where the cutoff energy is proportional to the pump wave intensity, in GQDs the cutoff energy scales with the square root of the field strength amplitude. A detailed time-frequency analysis of the entire range of HHG spectrum is presented using a wavelet transform. The analysis reveals intricate details of the spectral and temporal fine structures of HHG, offering insights into the various HHG mechanisms in GQDs.

Topological superconductivity with large Chern numbers in a ferromagnetic metal-superconductor heterostructure. (arXiv:2307.14838v2 [cond-mat.supr-con] UPDATED)
Yingwen Zhang, Dao-Xin Yao, Zhi Wang

The ferromagnetic metal-superconductor heterostructure with interface Rashba spin-orbit hopping is a promising candidate for topological superconductivity. We study the interplay between the interface Rashba hopping and the intrinsic Dresselhaus spin-orbit coupling in this heterostructure, and demonstrate rich topological phases with five distinct Chern numbers. In particular, we find a topological state with a Chern number as large as four in the parameter space of the heterostructure. We calculate the Berry curvatures that construct the Chern numbers, and show that these Berry curvatures induce anomalous thermal Hall transport of the superconducting quasiparticles. We reveal chiral edge states in the topological phases, as well as helical edge states in the trivial phase, and show that the wave functions of these edge states mostly concentrate on the ferrometal layer of the heterostructure.

Gauge field fluctuation corrected QED3 effective action by fermionic particle-vortex duality. (arXiv:2308.06916v2 [hep-th] UPDATED)
Wei-Han Hsiao

We develop a non-perturbative framework to incorporate gauge field fluctuations into QED3 effective actions in the infrared by fermionic particle-vortex duality. The utility is demonstrated by the application to models containing N species of 2-component Dirac fermions in a couple of solvable and interpretable electromagnetic backgrounds: N = 1 or 2. For the N = 1 model, we establish a correspondence between fermion Casimir energy at finite density and the magnetic Euler-Heisenberg Lagrangian, and we further evaluate the correction to their amplitudes. This in turn predicts the amplification of charge susceptibility and the reduction of magnetic permeability. We additionally supply physical interpretations to each component of our calculation as well as alternative derivations based on energy density measurements in different characteristic lengths. For N = 2, we show that the magnetic catalysis is erased in a U(1)$\times$U(1) QED3 and therefore there is no breakdown of chiral symmetry. Some reasoning is offered based on the properties of the lowest Landau level wave functions.

Optimization Algorithms for Multi-Species Spherical Spin Glasses. (arXiv:2308.09672v2 [math.PR] UPDATED)
Brice Huang, Mark Sellke

This paper develops approximate message passing algorithms to optimize multi-species spherical spin glasses. We first show how to efficiently achieve the algorithmic threshold energy identified in our companion work, thus confirming that the Lipschitz hardness result proved therein is tight. Next we give two generalized algorithms which produce multiple outputs and show all of them are approximate critical points. Namely, in an $r$-species model we construct $2^r$ approximate critical points when the external field is stronger than a "topological trivialization" phase boundary, and exponentially many such points in the complementary regime. We also compute the local behavior of the Hamiltonian around each. These extensions are relevant for another companion work on topological trivialization of the landscape.

Strong Topological Trivialization of Multi-Species Spherical Spin Glasses. (arXiv:2308.09677v2 [math.PR] UPDATED)
Brice Huang, Mark Sellke

We study the landscapes of multi-species spherical spin glasses. Our results determine the phase boundary for annealed trivialization of the number of critical points, and establish its equivalence with a quenched \emph{strong topological trivialization} property. Namely in the "trivial" regime, the number of critical points is constant, all are well-conditioned, and all approximate critical points are close to a true critical point. As a consequence, we deduce that Langevin dynamics at sufficiently low temperature has logarithmic mixing time.

Our approach begins with the Kac--Rice formula. We derive closed form expressions for some asymptotic determinants studied in (Ben Arous-Bourgade-McKenna 2023, McKenna 2021), and characterize the annealed trivialization phase by explicitly solving a suitable multi-dimensional variational problem. To obtain more precise quenched results, we develop general purpose techniques to avoid sub-exponential correction factors and show non-existence of \emph{approximate} critical points. Many of the results are new even in the $1$-species case.

Higher-order topological phases in crystalline and non-crystalline systems: a review. (arXiv:2309.03688v2 [cond-mat.mes-hall] UPDATED)
Yan-Bin Yang, Jiong-Hao Wang, Kai Li, Yong Xu

In recent years, higher-order topological phases have attracted great interest in various fields of physics. These phases have protected boundary states at lower-dimensional boundaries than the conventional first-order topological phases due to the higher-order bulk-boundary correspondence. In this review, we summarize current research progress on higher-order topological phases in both crystalline and non-crystalline systems. We firstly introduce prototypical models of higher-order topological phases in crystals and their topological characterizations. We then discuss effects of quenched disorder on higher-order topology and demonstrate disorder-induced higher-order topological insulators. We also review the theoretical studies on higher-order topological insulators in amorphous systems without any crystalline symmetry and higher-order topological phases in nonperiodic lattices including quasicrystals and hyperbolic lattices, which have no crystalline counterparts. We conclude the review by a summary of experimental realizations of higher-order topological phases and discussions on potential directions for future study.

Found 7 papers in prb
Date of feed: Fri, 15 Sep 2023 03:16:05 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)

Spatially anisotropic $S=1$ square-lattice antiferromagnet with single-ion anisotropy realized in a Ni(II) pyrazine-$n,{n}^{′}$-dioxide coordination polymer
Jamie L. Manson, Daniel M. Pajerowski, Jeffrey M. Donovan, Brendan Twamley, Paul A. Goddard, Roger Johnson, Jesper Bendix, John Singleton, Tom Lancaster, Stephen J. Blundell, Jacek Herbrych, Peter J. Baker, Andrew J. Steele, Francis L. Pratt, Isabel Franke-Chaudet, Ross D. McDonald, Alex Plonczak, and Pascal Manuel
Author(s): Jamie L. Manson, Daniel M. Pajerowski, Jeffrey M. Donovan, Brendan Twamley, Paul A. Goddard, Roger Johnson, Jesper Bendix, John Singleton, Tom Lancaster, Stephen J. Blundell, Jacek Herbrych, Peter J. Baker, Andrew J. Steele, Francis L. Pratt, Isabel Franke-Chaudet, Ross D. McDonald, Alex Plonczak, and Pascal Manuel

The $\mathrm{Ni}{(\mathrm{NCS})}_{2}{(\mathrm{pyzdo})}_{2}$ coordination polymer is found to be an $S=1$ spatially anisotropic square lattice with easy-axis single-ion anisotropy. This conclusion is based upon considering in concert the experimental probes x-ray diffraction, magnetic susceptibility,…

[Phys. Rev. B 108, 094425] Published Thu Sep 14, 2023

Anharmonicity and structural phase transition in the Mott insulator ${\mathrm{Cu}}_{2}{\mathrm{P}}_{2}{\mathrm{O}}_{7}$
Svitlana Pastukh, Paweł T. Jochym, Oleksandr Pastukh, Jan Łażewski, Dominik Legut, and Przemysław Piekarz
Author(s): Svitlana Pastukh, Paweł T. Jochym, Oleksandr Pastukh, Jan Łażewski, Dominik Legut, and Przemysław Piekarz

Ab initio investigations of the structural, electronic, and dynamical properties of the high-temperature $β$ phase of copper pyrophosphate were performed using density functional theory. The electronic band structure shows the Mott insulating state due to electron correlations in the copper ions. By…

[Phys. Rev. B 108, 104104] Published Thu Sep 14, 2023

Band structure, $g$-factor, and spin relaxation in $n$-type InAsP alloys
Sunil K. Thapa, Rathsara R. H. H. Mudiyanselage, Thalya Paleologu, Sukgeun Choi, Zhuo Yang, Y. Kohama, Y. H. Matsuda, Joseph Spencer, Brenden A. Magill, Chris J. Palmstrøm, Christopher J. Stanton, and Giti A. Khodaparast
Author(s): Sunil K. Thapa, Rathsara R. H. H. Mudiyanselage, Thalya Paleologu, Sukgeun Choi, Zhuo Yang, Y. Kohama, Y. H. Matsuda, Joseph Spencer, Brenden A. Magill, Chris J. Palmstrøm, Christopher J. Stanton, and Giti A. Khodaparast

We present experimental and theoretical studies of the magneto-optical properties of $n$-type ${\mathrm{InAs}}_{x}{\mathrm{P}}_{1−x}$ films in ultrahigh magnetic fields at room temperature. We compare Landau level and band structure calculations with observed cyclotron resonance (CR) measurements an…

[Phys. Rev. B 108, 115202] Published Thu Sep 14, 2023

Temperature evolution of domains and intradomain chirality in $1T−{\mathrm{TaS}}_{2}$
Boning Yu, Ghilles Ainouche, Manoj Singh, Bishnu Sharma, James Huber, and Michael C. Boyer
Author(s): Boning Yu, Ghilles Ainouche, Manoj Singh, Bishnu Sharma, James Huber, and Michael C. Boyer

We use scanning tunneling microscopy to study the temperature evolution of the atomic-scale properties of the nearly commensurate charge density wave (NC-CDW) state of the low-dimensional material $1T\text{−}{\mathrm{TaS}}_{2}$. Our measurements at 203, 300, and 354 K, roughly spanning the temperatu…

[Phys. Rev. B 108, 115421] Published Thu Sep 14, 2023

Experimental verification of band convergence in Sr and Na codoped PbTe
Yuya Hattori, Shunsuke Yoshizawa, Keisuke Sagisaka, Yuki Tokumoto, Keiichi Edagawa, Takako Konoike, Shinya Uji, and Taichi Terashima
Author(s): Yuya Hattori, Shunsuke Yoshizawa, Keisuke Sagisaka, Yuki Tokumoto, Keiichi Edagawa, Takako Konoike, Shinya Uji, and Taichi Terashima

Scanning tunneling microscopy (STM) and transport measurements have been performed to investigate the electronic structure and its temperature dependence in heavily Sr and Na codoped PbTe, which is recognized as one of the most promising thermoelectric (TE) materials. Our main findings are as follow…

[Phys. Rev. B 108, 125119] Published Thu Sep 14, 2023

Electronic excitations in $5{d}^{4}\phantom{\rule{4pt}{0ex}}J=0\phantom{\rule{4pt}{0ex}}{\mathrm{Os}}^{4+}$ halides studied by resonant inelastic x-ray scattering and optical spectroscopy
P. Warzanowski, M. Magnaterra, P. Stein, G. Schlicht, Q. Faure, Ch. J. Sahle, T. Lorenz, P. Becker, L. Bohatý, M. Moretti Sala, G. Monaco, P. H. M. van Loosdrecht, and M. Grüninger
Author(s): P. Warzanowski, M. Magnaterra, P. Stein, G. Schlicht, Q. Faure, Ch. J. Sahle, T. Lorenz, P. Becker, L. Bohatý, M. Moretti Sala, G. Monaco, P. H. M. van Loosdrecht, and M. Grüninger

The cubic halides K2OsCl6, K2OsBr6, and Rb2OsBr6 are found to be excellent realizations of spin-orbit-entangled nonmagnetic J=0 compounds in the intermediate coupling regime. The two complementary techniques of resonant inelastic x-ray scattering and optical spectroscopy allow the authors to draw a comprehensive picture of the electronic excitations and to assess the electronic structure. The accurate set of electronic parameters such as spin-orbit coupling, Hund’s coupling, crystal-field splitting, Mott gap, and charge-transfer energy will serve as a solid reference for future studies on Os compounds.

[Phys. Rev. B 108, 125120] Published Thu Sep 14, 2023

Phonon-mediated dark to bright plasmon conversion
Benjamin Rousseaux, Yanko Todorov, Angela Vasanelli, and Carlo Sirtori
Author(s): Benjamin Rousseaux, Yanko Todorov, Angela Vasanelli, and Carlo Sirtori

Unlocking the full potential of nanophotonic devices involves the engineering of their intrinsic optical properties. Here, the authors investigate a quantum theory that treats the interaction between quantum-confined plasmons and optical phonons in semiconductors. This theory allows computation of the optical response beyond the conventional Drude-Lorentz model. In particular, it predicts new effects, such as an oscillator-strength transfer mechanism between phonons and dark plasmon modes.

[Phys. Rev. B 108, 125417] Published Thu Sep 14, 2023

Found 3 papers in prl
Date of feed: Fri, 15 Sep 2023 03:16:05 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)

Direct Observation of Topological Phonons in Graphene
Jiade Li, Jiangxu Li, Jilin Tang, Zhiyu Tao, Siwei Xue, Jiaxi Liu, Hailin Peng, Xing-Qiu Chen, Jiandong Guo, and Xuetao Zhu
Author(s): Jiade Li, Jiangxu Li, Jilin Tang, Zhiyu Tao, Siwei Xue, Jiaxi Liu, Hailin Peng, Xing-Qiu Chen, Jiandong Guo, and Xuetao Zhu

New experiments reveal graphene’s exotic phonon spectrum with unprecedented detail and completeness.

[Phys. Rev. Lett. 131, 116602] Published Thu Sep 14, 2023

Topological Circular Dichroism in Chiral Multifold Semimetals
Junyeong Ahn and Barun Ghosh
Author(s): Junyeong Ahn and Barun Ghosh

Uncovering the physical contents of the nontrivial topology of quantum states is a critical problem in condensed matter physics. Here, we study the topological circular dichroism in chiral semimetals using linear response theory and first-principles calculations. We show that, when the low-energy sp…

[Phys. Rev. Lett. 131, 116603] Published Thu Sep 14, 2023

Control of Active Brownian Particles: An Exact Solution
Marco Baldovin, David Guéry-Odelin, and Emmanuel Trizac
Author(s): Marco Baldovin, David Guéry-Odelin, and Emmanuel Trizac

Control of stochastic systems is a challenging open problem in statistical physics, with a wealth of potential applications from biology to granulates. Unlike most cases investigated so far, we aim here at controlling a genuinely out-of-equilibrium system, the two dimensional active Brownian particl…

[Phys. Rev. Lett. 131, 118302] Published Thu Sep 14, 2023

Found 1 papers in prx
Date of feed: Fri, 15 Sep 2023 03:16:05 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)

Observation of Self-Patterned Defect Formation in Atomic Superfluids–from Ring Dark Solitons to Vortex Dipole Necklaces
Hikaru Tamura, Cheng-An Chen, and Chen-Lung Hung
Author(s): Hikaru Tamura, Cheng-An Chen, and Chen-Lung Hung

The interaction between a superfluid and an enclosing circular box generates a ring-shaped dark soliton that evolves into a complex vortex structure, showing a novel way of generating structured topological defects.

[Phys. Rev. X 13, 031029] Published Thu Sep 14, 2023

Found 3 papers in acs-nano
Date of feed: Thu, 14 Sep 2023 13:06:59 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] Isomer Discrimination via Defect Engineering in Monolayer MoS2
Bin Han, Sai Manoj Gali, Shuting Dai, David Beljonne, and Paolo Samorì

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ACS Nano
DOI: 10.1021/acsnano.3c04194

[ASAP] Highly Durable and Efficient Seawater Electrolysis Enabled by Defective Graphene-Confined Nanoreactor
Zhichao Gong, Jingjing Liu, Minmin Yan, Haisheng Gong, Gonglan Ye, and Huilong Fei

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ACS Nano
DOI: 10.1021/acsnano.3c05749

[ASAP] Graphene Field Effect Biosensor for Concurrent and Specific Detection of SARS-CoV-2 and Influenza
Neelotpala Kumar, Dalton Towers, Samantha Myers, Cooper Galvin, Dmitry Kireev, Andrew D. Ellington, and Deji Akinwande

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.3c07707