arXiv subjects

Abhinava Chatterjee

Publications and source records attributed to Abhinava Chatterjee.

10 recordsLinked to original sources

arXiv2026

Nonlinear Tellegen limit

The Tellegen limit is the fundamental electromagnetic stability bound on magnetoelectric media. We show that nonlinear magnetoelectric coupling gives rise to a new Tellegen limit, which we term the nonlinear Tellegen limit. Unlike the linear Tellegen limit, which is fixed by material parameters, the nonlinear Tellegen limit is field-tunable -- a static electric or magnetic field drives the system toward electromagnetic instability at a material-specific critical field determined by the magnetic point group symmetry. The approach to this limit is accompanied by a field-tunable Faraday rotation that grows linearly with the applied field and is bounded from above by a universal maximum set by the nonlinear Tellegen limit -- beyond which the medium becomes electromagnetically unstable. We demonstrate the nonlinear Tellegen limit and the field-space stability phase diagram in two magnetically ordered material systems -- a d-wave altermagnet and an M-type hexagonal ferrite -- showing that the symmetry of the magnetic point group governs both the structure of the nonlinear magnetoelectric tensor and the resulting electromagnetic instability.

cond-mat.mtrl-sci↗

arXiv2026

Perfect Nonreciprocal Axion-polaritons

Dynamical axion describes a massive axion quasiparticle that arises from fluctuations of the magnetic order parameter. These fluctuations couple to electromagnetic fields, forming axion-polaritons -- collective modes that are physically magnon-polaritons. We show that under appropriate static external electric and magnetic fields, axion-polaritons acquire a nonreciprocal dispersion, $\omega(\textbf{k}) \neq \omega(-\textbf{k})$, arising intrinsically from direction-dependent axion-photon coupling. Strikingly, we identify a regime of \textit{perfect nonreciprocity} in which the photon propagating in one direction is completely decoupled from the axion while the counter-propagating photon hybridizes strongly. Furthermore, the nonreciprocal dispersion manifests as an optical isolator -- a device transmitting light preferentially in one direction. Our results establish nonreciprocal axion-polaritons as a powerful probe of axion quasiparticles and suggest experimentally accessible routes for their detection.

cond-mat.mes-hall↗

arXiv2026

Phonon circular birefringence and polarization-filter in Magnetic Topological Insulators

The surface phonon Hall viscosity (PHV)-an acoustic analog of axion electrodynamics-emerges from the strain response of magnetic topological insulators and gives rise to novel acoustic phenomena. In this work, we propose a previously unexplored effect: a phonon polarization-filter mechanism induced by the surface PHV, which generates an interface phonon mode with its frequency below the bulk mode frequency. This interface mode possesses a specific circular polarization and therefore acts as a polarization filter, confining only phonons with the matching polarization at the interface. Magnetic topological insulators can thus selectively transmit one type of circularly polarized phonon mode, enabling the manipulation of phonon polarization and angular momentum. In addition, we further develop a generalized scattering framework to study the effect of an injected acoustic wave from a trivial insulator to a magnetic topological insulator with both normal and oblique incidence, and discuss the phenomena of surface acoustic Faraday rotation and longitudinal-transverse mode conversion. Our results establish surface Hall viscosity as a powerful mechanism for engineering axial phonon states and open new avenues for topological phononic devices based on phonon angular momentum.

cond-mat.mes-hall↗

arXiv2026

Efficiently gate-tunable ferromagnetism in ferromagnetic semiconductor-Dirac semimetal p-n heterojunctions

We use molecular beam epitaxy to develop a gate tunable p-n heterojunction that interfaces a canonical Dirac semimetal, Cd$_3$As$_2$, and a ferromagnetic semiconductor, In$_{1-x}$Mn$_x$As, with perpendicular magnetic anisotropy. Measurements of the anomalous Hall effect in top-gated Cd$_3$As$_2$/In$_{1-x}$Mn$_x$As devices show that the ferromagnetic Curie temperature ($T_\mathrm{C}$) can be efficiently tuned using a modest gate voltage of $\sim 10$ V, corresponding to a sensitivity to electric field ($E$) of $\Delta T_{\mathrm{C}}/\Delta E \sim 10$ K/MV/cm). The voltage tuning of $T_\mathrm{C}$ saturates near the charge neutrality point of Cd$_3$As$_2$ and vanishes at positive gate voltage in appropriately designed heterostructures. This non-monotonic behavior cannot be explained solely by hole-mediated ferromagnetism in the In$_{1-x}$Mn$_x$As alone, suggesting an interaction between the Dirac semimetal and the ferromagnetic semiconductor. Our results identify Cd$_3$As$_2$/In$_{1-x}$Mn$_x$As heterojunctions as a potentially attractive platform for studying emergent phenomena arising from the interplay between broken symmetry, topology, and magnetism in a topological semimetal.

cond-mat.mes-hall↗

arXiv2026

Surface Phonon Hall Viscosity Induced Phonon Chirality and Nonreciprocity in Magnetic Topological Insulator Films

The surface half-quantum Hall effect, a hallmark consequence of axion electrodynamics, can be induced by gapping out the surface states of topological insulators through surface magnetization, and has led to a variety of topological response phenomena observed in experiments. In this work, we investigate phonon dynamics originating from an acoustic analog - the surface phonon Hall viscosity - that can also occur at the surface of magnetic topological insulators. This surface phonon Hall viscosity stems from the Nieh-Yan action in the strain response of topological insulators, where strain acts as the effective vierbein field for the bulk low-energy massive Dirac fermions. Crucially, this viscosity term entangles phonon dynamics with surface magnetization. In magnetic topological insulator films, we find that this interaction causes acoustic phonons to become chiral when the magnetization at the top and bottom surfaces is parallel, and nonreciprocal when it is anti-parallel. We further discuss potential experimental signatures of phonon dynamics induced by surface phonon Hall viscosity, specifically the phonon thermal Hall effect and magnon-polarons.

cond-mat.mes-hall↗

arXiv2025

QMBench: A Research Level Benchmark for Quantum Materials Research

We introduce QMBench, a comprehensive benchmark designed to evaluate the capability of large language model agents in quantum materials research. This specialized benchmark assesses the model's ability to apply condensed matter physics knowledge and computational techniques such as density functional theory to solve research problems in quantum materials science. QMBench encompasses different domains of the quantum material research, including structural properties, electronic properties, thermodynamic and other properties, symmetry principle and computational methodologies. By providing a standardized evaluation framework, QMBench aims to accelerate the development of an AI scientist capable of making creative contributions to quantum materials research. We expect QMBench to be developed and constantly improved by the research community.

cond-mat.mtrl-sci↗

arXiv2025

Discovery of a Highly Anisotropic Type-II Ferromagnetic Weyl State Exhibiting a 3D Quantum Hall Effect

Topological semimetals, particularly Weyl semimetals (WSMs), are crucial platforms for exploring emergent quantum phenomena due to their unique electronic structures and potential to transition into various topological phases. In this study, we report the discovery of a ferromagnetic (FM) type-II WSM in Mn(Bi1-xSbx)4Te7, which exhibits a remarkable three-dimensional (3D) quantum Hall effect (QHE). By precisely tuning the chemical potential through Sb doping, we obtained samples with the Fermi level near the charge neutrality point for x = ~ 0.27. This was confirmed by spectroscopy measurements (ARPES and STS), and these samples showed strong quantum oscillations along with a key transport signature of a Weyl state - chiral anomaly, and Fermi surface reconstruction driven by FM ordering. Our theoretical analysis indicates that this Weyl state evolves from a parent nodal ring state, where higher-order k-terms split the nodal line into type-II Weyl nodes. The Weyl state exhibits significant anisotropy, characterized by a pronounced reduction in Fermi velocity along the kz-axis, likely accounting for the observed 3D QHE. These results not only highlight the exceptional tunability of the Mn(Bi1-xSbx)4Te7 system, where precise control of the chemical potential and magnetic properties opens access to novel quantum phases, but also advance the understanding of FM WSMs.

cond-mat.mtrl-sci↗

arXiv2024

Localized interfacial Phonon Modes at the Electronic Axion Domain Wall

The most salient feature of electronic topological states of matter is the existence of exotic electronic modes localized at the surface or interface of a sample. In this work, in an electronic topological system, we demonstrate the existence of localized phonon modes at the domain wall between topologically trivial and non-trivial regions, in addition to the localized interfacial electronic states. In particular, we consider a theoretical model for the Dirac semimetal with a gap opened by external strains and study the phonon dynamics, which couples to electronic degrees of freedom via strong electron-phonon interaction. By treating the phonon modes as a pseudo-gauge field, we find that the axion type of terms for phonon dynamics can emerge in gapped Dirac semimetal model and lead to interfacial phonon modes localized at the domain wall between trivial and non-trivial regimes that possess the axion parameters 0 and {\pi}, respectively. We also discuss the physical properties and possible experimental probe of such interfacial phonon modes.

cond-mat.mes-hall↗

arXiv2021

Twisted superfluid and supersolid phases of triplons in bilayer honeycomb magnets

We demonstrate that low-lying triplon excitations in a bilayer Heisenberg antiferromagnet provide a promising avenue to realize magnetic analogs of twisted superfluid and supersolid phases that were recently reported for two-component ultracold atomic condensate in an optical lattice. Using a cluster Gutzwiller mean-field theory, we establish that Dzyaloshinskii-Moriya interactions (DMI), that are common in many quantum magnets, stabilize these phases in a magnetic system, in contrast to the pair hopping process that is necessary for ultracold atoms. The critical value of DMI for transition to the twisted superfluid and twisted supersolid phases depends on the strength of the (frustrated) interlayer interactions that can be tuned by applying external pressure on and / or shearing force between the layers. Furthermore, we show that the strength of DMI can be controllably varied by coupling to tailored circularly polarized light. Our results provide crucial guidance for the experimental search of twisted superfluid and supersolid phases of triplons in real quantum magnets.

cond-mat.str-el↗

arXiv2018

Diffusion with Resetting Inside a Circle

We study the Brownian motion of a particle in a bounded circular 2-dimensional domain, in search for a stationary target on the boundary of the domain. The process switches between two modes: one where it performs a two-dimensional diffusion inside the circle and one where it travels along the one-dimensional boundary. During the diffusion, the Brownian particle resets to its initial position with a constant rate $r$. The Fokker-Planck formalism allows us to calculate the mean time to absorption (MTA) as well as the optimal resetting rate for which the MTA is minimized. From the derived analytical results the parameter regions where resetting reduces the search time can be specified. We also provide a numerical method for the verification of our results.

cond-mat.stat-mech↗