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## О перколяционном режиме объемного транспорта в топологическом изоляторе Bi1.08Sn0.02Sb0.9Te2S

Письма в Журнал экспериментальной и теоретической физики. 2022. Т. 115. № 4. С. 270-276.

Pudalov V., Сахин В. О., Куковицкий Е. Ф., Таланов Ю. И., Тейтельбаум Г. Б., Morgun L., Борисов А. Э., Усольцев А. С.

The formation of nanosized charge droplets in the bulk of a three-dimensional topological insulator

Bi1.08Sn0.02Sb0.9Te2S was evidenced using electron spin resonance. Since electrons and holes are “locked” in

these droplets far apart from each other, their participation in bulk conductivity is possible only due to thermal

activation or to variable range hopping. Our transport measurements give evidence that at relatively high

temperatures conduction follows the activation behavior with the activation energies which due to percolation

may be much smaller than the half of the band gap. We also demonstrate that the variable range hoping

replaces the activated transport at sufficiently low temperatures.

Mal'shukov A., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 101 P. 134514-1-134514-7

A nonuniform in-plane Zeeman field can induce spontaneous supercurrents of spin-orbit-coupled electrons in
superconducting two-dimensional systems and thin films. In this work it is shown that current vortices can be
created at the ends of a long homogeneously magnetized strip of a ferromagnetic insulator, which is deposited on
the surface of a three-dimensional topological insulator. The s-wave superconductivity ...

Added: January 20, 2021

Aronzon B. A., Oveshnikov L. N., Prudkoglyad V.A. et al., Journal of Magnetism and Magnetic Materials 2018 Vol. 459 No. 1 P. 331-334

Structural, magnetic and magnetotransport properties of (Bi1-xEux)2Se3 thin films have been studied experimentally as a function of Eu content. The films were synthesized by MBE. It is demonstrated that Eu distribution is not uniform, it enter quint-layers forming inside them plain (pancake-like) areas containing Eu atoms, which sizes and concentration increase with the growth of Eu content. Positive ...

Added: July 13, 2018

Kuntsevich A., Materials 2022 Vol. 14 No. 24 P. 7528-7528

Search for doped superconducting topological insulators is of prime importance for new quantum technologies. We report on fabrication of Sr-doped Bi2Te3 single crystals. We found that Bridgman grown samples have p-type conductivity in the low 10^19 cm^(−3), high mobility of 4000 cm^2*V^(−1)s^(−1), crystal structure independent on nominal dopant content, and no signs of superconductivity. We also studied molecular ...

Added: June 17, 2022

Мальшуков А. Г., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 P. 035301-1-035301-7

A nonstationary anomalous Hall current is calculated for a voltage biased Josephson junction, which is composed of two s-wave superconducting contacts deposited on the top of a three-dimensional topological insulator (TI). A homogeneous Zeeman field was assumed at the surface of the TI. The problem has been considered within the ballistic approximation and on the ...

Added: March 11, 2020

Овешников Л. Н., Нехаева Е. И., Прудкогляд В. А. et al., Письма в Журнал экспериментальной и теоретической физики 2016 Т. 104 № 9 С. 651-657

В работе исследовалась магнетопроводимость тонких пленок Bi2Se3 с защитным слоем Se, выра
щенных на подложках (111) BaF2. Наблюдаемая отрицательная магнетопроводимость в малых полях,
обусловленная эффектом слабой антилокализации, так же как и осцилляции Шубникова–де Гааза в
больших полях, определяется только перпендикулярной к плоскости пленки компонентой магнитного
поля. Полученные экспериментальные результаты могут быть разумно объяснены в предположении на
личия в исследуемых пленках ...

Added: December 6, 2016

Burmistrov I., Repin E., JETP Letters 2015 Vol. 148 No. 3 P. 509

We explore a combined effect of hexagonal warping and a finite effective mass on both the tunneling density of electronic surface states and the structure of Landau levels of 3D topological insulators. We find the increasing warping to transform the square-root van Hove singularity into a logarithmic one. For moderate warping, an additional logarithmic singularity ...

Added: December 3, 2016

Frolov A. V., Orlov A. P., Sinchenko A. A. et al., Journal of Physics: Conference Series 2018 Vol. 941 P. 1-4

We report preparation of nanoribbons (crossection ~ 250*25 nm2) by focused ion beam etching of single-crystalline Bi2Se3 and detailed measurements of their magnetoresistance at temperatures down to 4.2 K, magnetic field up to 9 T. In a magnetic field parallel to the axis of nanowire the magnetoresistance shows up oscillations. Surprisingly, the Fourier analysis shows ...

Added: February 25, 2018

Backens S., Shnirman A., Makhlin Y., JETP Letters 2022 Vol. 116 No. 12 P. 891-895

We consider Majorana zero modes in a Josephson junction on top of a topological insulator in transverse magnetic field. Majorana zero modes reside at periodically located nodes of Josephson vortices. We find that hybridization of these modes is prohibited by symmetries of the problem at vanishing chemical potential, which ensures better protection of zero modes ...

Added: December 10, 2022

S. V. Demishev, Gilmanov M. I., Samarin A. N. et al., Applied Magnetic Resonance 2020 Vol. 51 No. 1 P. 71-84

The low temperature (T < 5 K) electron spin resonance in topological Kondo insulator SmB6 is investigated. It is shown that spin relaxation time of the paramagnetic centers responsible for low temperature electron spin resonance in SmB6 is about ~ 10−8 s, which exceeds by five orders of magnitude the widely accepted spin and charge fluctuation time ~ 10−13 s in the homogeneous ...

Added: December 24, 2020

Ефимкин Д. К., Yu.E. Lozovik, A.A. Sokolik, Journal of Magnetism and Magnetic Materials 2012 Vol. 324 No. 21 P. 3610-3612

Collective plasmon excitations in a helical electron liquid on the surface of strong three-dimensional topological insulator are considered. The properties and internal structure of these excitations are studied. Due to spin-momentum locking in helical liquid on a surface of topological insulator, the collective excitations should manifest themselves as coupled charge- and spin-density waves. ...

Added: March 14, 2013

A.G. Mal'shukov, Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 P. 064515-1-064515-7

It is shown that the spin-orbit and Zeeman interactions result in phase shifts of Andreev-reflected
holes propagating at the surface of a topological insulator, or in Rashba spin-orbit-coupled two
dimensional normal metals, which are in a contact with an s-wave superconductor. Due to interference
of holes reflected through different paths of Andreev interferometer the electric current through
external contacts ...

Added: February 6, 2019

Nagaev K., Remizov S., Shapiro D.S., JETP Letters 2018 Vol. 108 P. 664-669

We calculate the frequency-dependent shot noise in the edge states of a two-dimensional topological insulator coupled to a magnetic impurity with spin S = 1/2 of arbitrary anisotropy. If the anisotropy is absent, the noise is purely thermal at low frequencies, but tends to the Poisson noise of the full current I at high frequencies. If the interaction only ...

Added: October 29, 2021

Makhlin Y., Silaev M., Volovik G. E., Physical Review B: Condensed Matter and Materials Physics 2014 Vol. 89 P. 174502

We provide topological classification of possible phases with the symmetry of the planar phase of superfluid He3. Compared to the B phase [class DIII in classification of A. Altland and M. R. Zirnbauer, Phys. Rev. B 55, 1142 (1997)], it has an additional symmetry, which modifies the topology. We analyze the topology in terms of ...

Added: October 15, 2016

Alexander P. Protogenov, Verbus V. A., Chulkov E., Physical Review B: Condensed Matter and Materials Physics 2013 Vol. 88 No. 19 P. 195431-1-195431-4

We use the N-terminal scheme for studying the edge-state transport in two-dimensional topological insulators. We find the universal nonlocal response in the ballistic transport approach. This macroscopic exhibition of the topological order offers different areas for applications. ...

Added: December 25, 2013

S.V. Novikov, Journal of Chemical Physics 2017 Vol. 146 No. 2 P. 024504-1 -024504-8

Hopping charge transport in amorphous semiconductors having spatially correlated exponential density of states has been considered. Average carrier velocity is exactly calculated for the quasi-equilibrium (nondispersive) transport regime. We suggest also a heuristic approach for the consideration of the carrier velocity for the non-equilibrium dispersive regime. ...

Added: March 22, 2017

Karabassov T., Vasenko A., Известия Уфимского научного центра РАН 2021 Т. 1 С. 10-16

Materials that possess strong spin-orbit interaction have provoked great interest over the past few years, in
particular, in the actively developing field of quantum calculations. A topological insulator is a good example of
such a material. The topological insulator has high surface conductivity, whereas in the body it shows the properties
of an insulator, this being a purely ...

Added: December 30, 2020

Verbus V. A., Protogenov A. P., Chulkov E., / Cornell University. Series cond-mat "arxiv.org". 2014. No. 1406.1507.

Weyl semimetal is a three-dimensional material with a conical spectrum near an even number of point nodes, where two bands touch each other. Here we study spectral properties of surface electron states in such a system. We show that the density of surface states possesses a logarithmic singularity for the energy to 0. It decreases ...

Added: March 8, 2016

49601782, Ikhsanov R., Novikov S. V., Chemical Physics 2014 Vol. 440 P. 1-7

We have compared time-of-flight curves predicted by hopping and multiple trapping models with the Gaussian and exponential site/trap energy distributions, fitting Monte-Carlo predictions of the former with numerical calculations of the latter in a wide time domain using logarithmic coordinates lg j–lg t for the characterization of current shapes and an estimation of transit times. As a ...

Added: February 28, 2015

Piatrusha S. U., Khrapai V., Kvon Z. D. et al., Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 96 No. 245417 P. 1-10

We investigate lateral p−n junctions, electrostatically defined in 14-nm-wide HgTe-based quantum wells (QWs) with inverted band structure. The p−n junction resistances are close to h/2e2, consistent with some previous experiments on 8–10nm QWs, and the current-voltage characteristics are highly linear, indicating the transport via ballistic helical edge states. Shot noise measurements are performed in order to further verify the underlying transport mechanism. We ...

Added: February 1, 2019

Krasikov K. M., Bogach A. V., S. V. Demishev et al., Journal of Magnetism and Magnetic Materials 2021 Vol. 545 Article 168796

The nature of charge transport and magnetization anisotropy was investigated in the ErB12 antiferromagnetic metal with both cooperative Jahn-Teller distortions of the fcc crystal structure and electronic instability (dynamic charge stripes). A butterfly pattern of the H-φ magnetic phase diagram in the (1 1 0) plane was reconstructed, including a large number of different magnetic phases separated from ...

Added: October 25, 2022

Галиуллин А. А., Соболевский О. А., Михайлов Н. Н. et al., В кн. : XXIV Уральская международная зимняя школа по физике полупроводников. : Институт физики металлов им. М.Н. Михеева УрО РАН, 2022. С. 153.

Демонстрируется влияние длины края двумерного топологического изолятора на основе квантовой 8 нм ямы HgTe на нелокальный транспорт. Предложена и реализована геометрия структуры типа длинного края. Показано, что вклад длинного края в кондактанс мал по сравнению с вкладом короткого края. Данная геометрия позволяет полностью поляризовать ток по спину. ...

Added: December 7, 2022

T. Karabassov, A.A. Golubov, Silkin V. M. et al., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 103 P. 224508-1-224508-9

Superconducting hybrid structures with topological order and induced magnetization offer a promising way to realize fault-tolerant quantum computation. However, the effect of the interplay between magnetization and the property of the topological insulator surface, otherwise known as spin-momentum locking on the superconducting proximity effect, still remains to be investigated. We relied on the quasiclassical self-consistent ...

Added: June 4, 2021

Kuntsevich A., Shupletsov A. V., Minkov G. M., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 P. 195431-1-195431-8

The phase of quantum magneto-oscillations is often associated with the Berry phase and is widely used to
argue in favor of topological nontriviality of the system (Berry phase 2πn + π). Nevertheless, the experimentally
determined value may deviate from 2πn + π arbitrarily, therefore more care should be made analyzing the
phase of magneto-oscillations to distinguish trivial systems ...

Added: September 10, 2018

A.S.Ioselevich, Sivak V. V., Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 95 P. 214205-1-214205-18

We theoretically study the conductivity in arrays of metallic grains due to the variable-range multiple cotunneling of electrons with short-range (screened) Coulomb interaction. The system is supposed to be coupled to random stray charges in the dielectric matrix that are only loosely bounded to their spatial positions by elastic forces. The flexibility of the stray ...

Added: October 26, 2017