arXiv subjects

M. V. Budantsev

Publications and source records attributed to M. V. Budantsev.

4 recordsLinked to original sources

arXiv2026

Giant Shubnikov-de Haas Oscillations with V-Shaped Minima in a High-Mobility Two-Dimensional Electron Gas: Experiment and Phenomenological Model

Giant Shubnikov-de Haas oscillations (SdHO) with V-shaped minima are experimentally studied in a high-mobility two-dimensional electron gas based on GaAs/AlGaAs heterostructures. A phenomenological model with two parameters (transport momentum relaxation time $τ_{\text{tr}}$ and quantum scattering time $τ_q$) is developed, accurately describing experimentally measured magnetoresistance over an unexpectedly wide range of magnetic fields (up to 3.5 T) and temperatures (from 2 K to 15 K). The model combines: (i) a quasiclassical density of states with a magnetic-field-dependent Gaussian broadening of Landau levels, (ii) a momentum relaxation time scaling with the density of states, and (iii) oscillations of the Fermi level at a fixed electron density. This model reproduces V-shaped oscillation minima with zero-resistance points, a smooth background of positive magnetoresistance, and enables the extraction of $τ_q$ and $τ_{\text{tr}}$ even in microstructures where ballistic and viscous effects dominate at low fields. As expected, the temperature dependence reveals that $τ_{\text{tr}}$ scales inversely with temperature due to acoustic phonon scattering, while $τ_q$ remains temperature-independent.

cond-mat.mes-hall↗

arXiv2013

Hysteretic phenomena in a 2DEG in quantum Hall effect regime studied in a transport experiment

We investigated experimentally non-equilibrium state of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime, studying the hysteresis of magnetoresistance of a 2DEG with a constriction. The large amplitude of the hysteresis enabled us to make the consistent phenomenological description of the hysteresis. We studied the dependence on the magnetic field sweep prehistory (minor loop measurements), recovered the anhysteretic curve, and studied the time dependence of the magnetoresistance. We showed that the hysteresis of magnetoresistance of a 2DEG in the QHE regime has significant phenomenological similarities with the hysteresis of magnetization of ferromagnetic materials, showing multistability, jumps of relaxation, and having the anhysteretic curve. Nevertheless, we revealed the crucial difference, manifested itself in an unusual inverted (anti-coercive) behavior of the magnetoresistance hysteresis. The time relaxation of the hysteresis has fast and slow regimes, similar to that of non-equilibrium magnetization of a 2DEG in QHE regime pointing to their common origin. We studied the dependence of the hysteresis loop area on the lithographic width of the constriction and found the threshold value of width $\sim$1.35 $μ$m beyond which the hysteresis is not observed. This points to the edge nature of the non-equilibrium currents (NECs) and allows us to determine the width of the NECs area ($\sim$0.5 $μ$m). We suggest the qualitative picture of the observed hysteresis, based on non-equilibrium redistribution of the electrons among the Landau level states and assuming huge imbalance between the population of bulk and edge electronic states.

cond-mat.mes-hall↗

arXiv2009

The Coulomb Blockade Resonant Breakdown Caused By The Quantum Dot Mechanical Oscillations

Influence of forced mechanical vibrations of a suspended single-electron transistor on electron tunneling through the quantum dot limited by the Coulomb blockade is investigated. It is shown that mechanical oscillations of the quantum dot lead to the Coulomb blockade breakdown, shown in sharp resonant peaks in the transistor conductance dependence on the excitation frequency at values corresponding to the mechanical oscillations eigen modes. Physical mechanism of the observed effect is considered. It is presumably connected with oscillations of the mutual electrical capacitances between the quantum dot and surrounding electrodes.

cond-mat.mes-hall↗

arXiv1998

2D Lattice of coupled Sinai billiards: metal or insulator at g<<1

We investigate the transport in a two-dimensional (2D) lattice of coupled Sinai billiards fabricated on the basis of a high-mobility 2D electron gas in GaAs/AlGaAs heterojunction. For the states with low reduced conductivity g<<1 an anomalously weak temperature dependence of g was found. The large negative magnetoresistance described by the Lorentz line-shape of the width corresponding to the half magnetic flux quantum through the area of the billiard is observed. In going from g>1 to g<<1 it strongly increases. The Shubnikov-de Haas oscillations and commensurability magnetoresistance peak are preserved at g<<1. The data suggest that the system studied behaves more like a metal than an insulator at g<<1 and is not described by the generally accepted picture of Anderson localization.

cond-mat.mes-hall↗