arXiv subjects

M. M. Glazov

Publications and source records attributed to M. M. Glazov.

At least 19 recordsLinked to original sources

arXiv2026

Self-balancing luminescence kinetics of charged excitons in WS$_2$ monolayer

Two-dimensional tungsten-based transition metal dichalcogenides exhibit a rich emission spectrum with distinct lines of exciton and biexciton states, neutral and charged, which are typically considered as independent entities. Here, we present a study of the emission kinetics of a WS$_2$ monolayer, demonstrating that these states together form a single interacting ensemble, with their population and depletion mutually coordinated with temperature. Dark trions make a long-lived contribution to the bright trion on a time scale of 200-300 picoseconds, and replenishment from dark states promotes intense luminescence of charged biexcitons. The developed self-consistent rate equation model reproduces the temperature dependence of the kinetics well, opening the way to controlling exciton states in such materials.

cond-mat.mes-hall↗

arXiv2026

Long-range exchange interaction controls the fine structure of excited trion states in semiconductor quantum dots

We develop a microscopic theory of the long-range electron-hole exchange interaction in charged excitons (trions) confined in semiconductor quantum dots. While the ground-state singlet trion remains degenerate in the spin component of unpaired charge carrier by time-reversal symmetry, excited trion states exhibit a rich fine structure resulting from the interplay of electron-electron and electron-hole exchange interactions. We derive the effective long-range exchange Hamiltonian for both the spin-$3/2$ heavy-hole and a simple spin-$1/2$ valence band models. The long-range exchange interaction mixes singlet and triplet trion configurations, giving rise to anisotropic fine-structure splittings and related polarization-dependent optical spectra determined by the quantum-dot shape. Analytical expressions are obtained for the long-range exchange parameters. The developed theory establishes a unified microscopic description of the fine structure of excited trions in semiconductor quantum dots and provides a framework for interpreting polarization-resolved optical spectroscopy of charged excitonic complexes.

cond-mat.mes-hall↗

arXiv2026

Intersubband electric dipole spin resonance in transition metal dichalcogenide heterobilayers

The theory of inter-spin-subband electric dipole spin resonance in transition metal dichalcogenide heterobilayers is proposed. Our symmetry analysis demonstrates that, in contrast to monolayers, the reduced symmetry of heterobilayers enables coupling between conduction band spin subbands by an electric field. We establish the optical selection rules for all six high-symmetry stacking configurations. The microscopic mechanism of the effect is identified as the spin-orbit coupling induced mixing of Bloch states from different conduction bands, which generates a non-zero momentum matrix element between the spin-split states. It also leads to the linear-in-wavevector spin-dependent terms in the effective Hamiltonian, i.e., the Rashba effect. Our estimates show that the rate of electric-dipole spin-flip transitions exceeds by far that of the magnetic-dipole transitions in transition metal dichalcogenide heterobilayers.

cond-mat.mes-hall↗

arXiv2026

Spectroscopy of Heat Transport and Violation of the Wiedemann--Franz Law in a GaAs Hydrodynamic Mesoscopic Channel

The Wiedemann--Franz law, which determines the universality of the ratio of thermal conductivity to electrical conductivity, is studied in the hydrodynamic electron transport regime, where electron--electron scattering predominates over scattering by disorder. In this case, the different relaxation of electric and thermal currents can lead to a violation of the Wiedemann--Franz law, which is expected to be even more pronounced in mesoscopic electron systems. This paper reports the propagation of hot electrons in a GaAs hydrodynamic narrow channel, studied using micrometer-resolution photoluminescence thermometry. A temperature dependence of the Lorenz number was obtained, indicating a violation of the Wiedemann--Franz law. The important role of narrow constrictions in this violation was also demonstrated, and theoretical arguments are presented.

cond-mat.mes-hall↗

arXiv2026

Odd viscosity and anomalous Hall effect in two dimensional electron systems with smooth disorder

A microscopic theory of odd viscosity in two-dimensional electron systems with smooth disorder and spin-orbit interaction is developed. It is shown that spin-orbit scattering in presence of spin polarization induced by magnetic field gives rise to an off-diagonal component of the viscosity tensor. Hydrodynamic equations for spin and electric currents are derived for electrons interacting with smooth disorder. The contribution of odd viscosity to the anomalous Hall effect is calculated.

cond-mat.mes-hall↗

arXiv2025

Photocurrents induced by k-linear terms in semiconductors and semimetals

We develop a six-band $\mathbf{k} \cdot \mathbf{p}$ model to describe the electronic structure and optical response of chiral multifold semimetals, such as RhSi. By means of invariants method we construct the effective Hamiltonian describing the states near the $Γ$-point of the Brillouin zone where the spin-orbit coupling and $\mathbf{k}$-linear Rashba terms, which are crucial for circular photogalvanic effect, are taken into account. The model is parameterized using tight-binding calculations. We compute the interband absorption spectrum, showing a linear-in-frequency dependence at low energies and a resonant feature near the spin-orbit splitting energy. Furthermore, we calculate the circular photogalvanic effect. In agreement with previous works the current generation rate at low frequencies exhibits a quantized low-frequency response, governed by the universal value $|\mathcal{C}| = 4$ for the effective topological charge. Our results provide an analytical framework for understanding the role of Rashba coupling and topology in the optoelectronic properties of multifold chiral semimetals.

cond-mat.mes-hall↗

arXiv2025

Terahertz radiation induced attractive-repulsive Fermi polaron conversion in transition metal dichalcogenide monolayers

We present a theoretical study of terahertz radiation-induced transitions between attractive and repulsive Fermi polaron states in monolayers of transition metal dichalcogenides. Going beyond the simple few-particle trion picture, we develop a many-body description that explicitly accounts for correlations with the Fermi sea of resident charge carriers. We calculate the rate of the direct optical conversion process which has a threshold where the terahertz photon energy equals to the Fermi polaron binding energy. This process features a characteristic frequency dependence near the threshold, due to final-state electron-exciton scattering related to the trion correlation with the Fermi sea hole. Furthermore, we demonstrate that intense terahertz pulses can significantly heat the electron gas via Drude absorption enabling an additional, indirect conversion mechanism through collisions between hot electrons and polarons, which exhibits a strong exponential dependence on the electron temperature. Our results reveal the important role of many-body correlations and thermal effects in the terahertz-driven dynamics of excitonic complexes in two-dimensional semiconductors.

cond-mat.mes-hall↗

arXiv2025

Nonreciprocal magnetic-field-induced second harmonic generation of exciton polaritons in ZnSe

We report on the optical second harmonic generation (SHG) on the 1S exciton-polariton resonance in bulk ZnSe that is subject to an external magnetic field applied perpendicular to the light wave vector $\mathbf k$ (Voigt geometry). For the symmetry allowed geometry with the $\mathbf{k}\parallel[111]$ crystal axes, the nonreciprocal dependence of the SHG intensity on the magnetic field direction is found. It is explained by an interference of the crystallographic and magnetic-field-induced SHG signals. Relative phases of these signals are evaluated from the rotational anisotropy diagrams. Phenomenological and microscopic models of the effect are developed. To the best of our knowledge, this is the first experimental observation of the nonreciprocal SHG in semiconductor crystals, and the first one for exciton-polaritons.

cond-mat.mes-hall↗

arXiv2025

Excitons and trions in CrSBr bilayers

We study theoretically the neutral and charged excitons in two-dimensional semiconductors with anisotropic dispersion of charge carriers. Such a situation is realized in CrSBr-based van der Waals heterostructures. We calculate the binding energies of excitons and trions and explore their dependence on the mass ratio, dielectric screening, and interlayer distance in bilayer structures. We also address the effects of exciton-light coupling, including the radiative decay and long-range electron-hole exchange interaction, and briefly analyze correlations between the excitons and the Fermi sea of resident electrons. The estimates for CrSBr bilayers are in reasonable agreement with recent experiments.

cond-mat.mes-hall↗

arXiv2025

Spin-valley polarization control in WSe$_2$ monolayers using photochemical doping

We report on the influence of a photochemical doping method on the spin-valley polarization degree ($P_{c}$) of excitons in WSe$_2$ monolayers. By varying the carrier density and transitioning from an excess of electrons (n-type) to an excess of holes (p-type), we observe a non-monotonic dependence of $P_{c}$ on the doping level. Using controlled, single-shot photochlorination steps, we unveil this non-monotonic behavior, with $P_{c}$ reaching a minimum value of less than 10$\%$ at 78 K near the charge neutrality point, while increasing by a factor of three at a hole density of $5 \times 10^{11} \,\mathrm{cm^{-2}}$. The impact of the doping on $P_{c}$ is explained using a phenomenological model that accounts for various mechanisms influencing exciton polarization dynamics, including exciton-carrier scattering processes and exciton-to-trion conversion rates. Among these, exciton-carrier collisions emerge as the dominant mechanism driving the observed variations in $P_{c}$, while the exciton effective lifetime remains nearly independent of doping. These findings highlight the potential of photochemical methods for investigating valley physics and for effectively tuning the exciton polarization degree in transition metal dichalcogenide monolayers.

cond-mat.mes-hall↗

arXiv2024

Electromagnetic field assisted exciton diffusion in moiré superlattices

We study exciton energy spectrum and their propagation in moiré superlattices formed in transition metal dichalcogenide heterobilayers. In such structures, as a result of weak interlayer interaction, an effective, moiré, potential acting on excitons arises. Usually, excitons are considered to be localized in such potential. Here we demonstrate that the coupling of optically active excitons with induced electromagnetic field produces linear in the wavevector energy dispersion even if the quantum mechanical tunneling between the localization sites is suppressed. The effect can be described as a result of the processes of virtual generation-recombination of excitons at the localization sites that results in the $ r^{-3}$ dependence of the transfer matrix element on the intersite distance $r$. Based on the calculated energy spectrum we study exciton propagation in moiré superlattices with allowance for the light-exciton interaction. We consider semiclassical diffusion of excitons and take into account exciton-phonon and exciton-static defect scattering. For these mechanisms the diffusion coefficient decreases with increase of the temperature. We also analyze the hopping propagation regime and demonstrate that the temperature dependence of the exciton diffusion coefficient is described by the power-law rather than by an exponential function of the temperature.

cond-mat.mes-hall↗

arXiv2024

Viscous hydrodynamics of excitons in van der Waals heterostructures

Excitons in semiconductors can form a variety of collective states leading to different regimes of exciton propagation. Here we theoretically demonstrate the possibility to reach the viscous hydrodynamic -- liquid-like -- regime of exciton propagation in two-dimensional materials, focusing on the mono- and bi-layers of transition metal dichalcogenides. This regime can be realized where the exciton-exciton collisions dominate over exciton-phonon and disorder scattering. We have derived the hydrodynamic-like set of equations describing viscous flow of interacting excitons based on the Boltzmann kinetic equation for the exciton distribution function. A comparison of various exciton propagation regimes including diffusive, viscous hydrodynamic, and superfluid regime is presented. Conditions which allow one to observe the hydrodynamic regime of exciton transport, and the role of material are discussed.

cond-mat.mes-hall↗

arXiv2024

Ultrafast exciton transport in van der Waals heterostructures

Excitons in van der Waals heterostructures based on atomically thin transition metal dichalcogenides are considered as potential candidates for the formation of a superfluid state in two-dimensional systems. A number of studies reported observations of ultrafast nondiffusive propagation of excitons in van der Waals heterostructures, which was considered by their authors as possible evidence of collective effects in excitonic systems. In this paper, after a brief analysis of exciton propagation regimes in two-dimensional semiconductors, an alternative model of ultrafast exciton transport is proposed, based on the formation of waveguide modes in van der Waals heterostructures and the radiation transfer by these modes.

cond-mat.mes-hall↗

arXiv2024

Longitudinal-transverse splitting and fine structure of Fermi polarons in two-dimensional semiconductors

Interaction of excitons with resident charge carriers in semiconductors gives rise to bound three-particle complexes, trions, whose optical response is conveniently described in the framework of many-body correlated Fermi polaron states. These states are formed as a result of correlation of photocreated trion with the Fermi sea hole and possess the angular momentum component of $\pm 1$ depending on the helicity of the photon. We study theoretically the energy spectrum fine structure of Fermi polarons in two-dimensional semiconductors based on transition metal dichalcogenides. We demonstrate both by the symmetry analysis and microscopic calculation that the Fermi polarons with nonzero in-plane wavevector $\bf k$ are split, similarly to the neutral exciton states, into the linearly polarized longitudinal and transverse, with respect to the $\bf k$, states. The origin of this longitudinal-transverse splitting is the long-range electron-hole exchange interaction that can be also described as the interaction of Fermi polarons with their induced electromagnetic field. The effective Hamiltonian describing the Fermi polaron fine structure is derived, and its parameters are determined from the microscopic model.

cond-mat.mes-hall↗

arXiv2024

Anomalous Hall effect in ultraclean electronic channels

Recent technological advances allow fabricating ultraclean two-dimensional electronic systems where the electron mean free path due to static disorder and phonons is much larger compared to the conducting channel width. It makes possible to realize novel, ballistic and hydrodynamic, regimes of electron transport resulting in drastic modifications of the normal Hall effect. Here we develop a theory of anomalous Hall effect -- generation of the electric field transverse to the flowing current unrelated to the Lorentz force action -- in ultraclean channels with two-dimensional electron gas and demonstrate that both in ballistic and hydrodynamic regimes the anomalous Hall effect, similarly to the normal one, strongly differs from that in the standard diffusive case. We take into account all relevant contributions to the anomalous Hall electric field and Hall voltage: the skew scattering of electrons, side-jump, and anomalous velocity effects that appear as a result of the spin-orbit coupling. We study both ballistic and hydrodynamic transport regimes which are realized depending on the relation between the electron-electron mean free path and the channel width. The role of electron-electron interactions is analyzed. Compact analytical expressions for the anomalous Hall field and voltage are derived. Possible experimental scenarios for observation of the anomalous Hall effect in ultraclean channels are briefly discussed.

cond-mat.mes-hall↗

arXiv2023

Diffusive-hydrodynamic transition in the anomalous Hall effect

We have developed a theory of the anomalous Hall effect in two-dimensional electron gas in the case where the time of electron-electron collisions is much smaller than the transport relaxation time. The transition between the diffusion transport regime, when the momentum relaxation length of electrons is much smaller than the channel width, and the hydrodynamic regime, when the momentum relaxation length exceeds the channel width, has been traced. The contributions of the anomalous velocity, wave packet shifts, and asymmetric scattering to the anomalous Hall field and voltage have been calculated. It has been shown that the anomalous Hall voltage caused by the asymmetric scattering can have a nontrivial coordinate dependence and change its sign depending on the specific scattering mechanism.

cond-mat.mes-hall↗

arXiv2023

Tailoring the electron and hole Landé factors in lead halide perovskite nanocrystals by quantum confinement and halide exchange

The tunability of the optical properties of lead halide perovskite nanocrystals makes them highly appealing for applications. Both, halide anion exchange and quantum confinement pave the way for tailoring their band gap energy. For spintronics applications, the Landé g-factors of electrons and hole are of great importance. By means of the empirical tight-binding and $\textbf{k}\cdot\textbf{p}$ methods, we calculate them for nanocrystals of the class of all-inorganic lead halide perovskites CsPb$X_3$ ($X = \text{I},\,\text{Br},\,\text{Cl}$). The hole g-factor as function of the band gap follows the universal dependence found for bulk perovskites, while for the electrons a considerable modification is predicted. Based on the $\textbf{k}\cdot\textbf{p}$ analysis we conclude that this difference arises from the interaction of the bottom conduction band with the spin-orbit split electron states. The model predictions are confirmed by experimental data for the electron and hole g-factors in CsPbI3 nanocrystals placed in a glass matrix, measured by time-resolved Faraday ellipticity in a magnetic field at cryogenic temperatures.

cond-mat.mes-hall↗

arXiv2023

Biaxial strain tuning of exciton energy and polarization in monolayer WS2

We perform micro-photoluminescence and Raman experiments to examine the impact of biaxial tensile strain on the optical properties of WS2 monolayers. A strong shift on the order of -130 meV per % of strain is observed in the neutral exciton emission at room temperature. Under near-resonant excitation we measure a monotonic decrease in the circular polarization degree under applied strain. We experimentally separate the effect of the strain-induced energy detuning and evaluate the pure effect coming from biaxial strain. The analysis shows that the suppression of the circular polarization degree under biaxial strain is related to an interplay of energy and polarization relaxation channels as well as to variations in the exciton oscillator strength affecting the long-range exchange interaction.

cond-mat.mtrl-sci↗