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On the Accuracy of Conductance Quantization in Spin-Hall Insulators
JETP Letters. 2019. Vol. 109. No. 2. P. 92–95.
Konyzheva S. K., E.S. Tikhonov, V.S. Khrapai
In contrast to the case of ordinary quantum Hall effect, the resistance of ballistic helical edge channels in typical quantum spin-Hall experiments is non-vanishing, additive and poorly quantized. Here we present a simple argument connecting this qualitative difference with a spin relaxation in the current/voltage leads in an experimentally relevant multi-terminal bar geometry. Both the finite lead resistance and the spin relaxation contribute to a non-vanishing four-terminal edge resistance, explaining poor quantization quality. We show that corrections to the four-terminal and two-terminal resistances in the limit of strong spin relaxation are opposite in sign, making a measurement of the spin relaxation resistance feasible, and estimate the magnitude of the effect in HgTe-based quantum wells.
Lukmanova R.M., Cohn I.A., Minakova V. E. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 111 No. 22 Article 224510
The magnetoresistance of superconductor–topological insulator–superconductor structures, with indium as the superconductor and TaSe3 as the topological insulator, shows steplike features on the resistance under magnetic fields. These resistance steps result from the suppression of superconductivity, induced by the superconducting proximity effect in both the bulk and surface states of the topological insulator. The position and ...
Added: March 11, 2026
Karabassov T., Bobkova I. V., Pavel M. Marychev et al., Beilstein Journal of Nanotechnology 2025 Vol. 17 P. 15–23
The diode effect in superconducting materials has been actively investigated in recent years. Plenty of different devices have been proposed as a platform to observe the superconducting diode effect. In this work, we discuss the possibility of a highly efficient superconducting diode design with controllable polarity. We propose a mesoscopic device that consists of two ...
Added: December 22, 2025
Flammini R., Hogan C., Colonna S. et al., Applied Physics Reviews 2025 Vol. 12 No. 1 Article 011336
Antimonene, the two-dimensional phase of antimony, appears in two distinct allotropes when epitaxially grown on Bi2Se3: the puckered asymmetric washboard (alpha) and buckled honeycomb (beta) bilayer structures. As-deposited antimony films exhibit varying proportions of single alpha and beta structures. We identify the conditions necessary for ordered, pure-phase growth of single to triple beta-antimonene bilayers. Additionally, ...
Added: September 6, 2025
Piasotski K., Lesser O., Reich A. et al., Physical Review B: Condensed Matter and Materials Physics 2025 Vol. 111 No. 17 Article 174527
Recent experiments on planar superconductor-topological insulator-superconductor (S-TI-S) junctions, e.g., in the Corbino geometry, have reported low-temperature nonzero Josephson currents in states with integer fluxoid (flux) induced in the junction by a perpendicular magnetic field. This effect was discussed in connection with Majorana zero modes localized in Josephson vortices of such junctions. Here, we provide an ...
Added: May 27, 2025
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
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
Karabassov T., Bobkova I. V., Golubov A. et al., Physical Review B: Condensed Matter and Materials Physics 2022 Vol. 106 No. 22 Article 224509
It is well-known that the ground state of homogeneous superconducting systems with spin-orbit
coupling (SOC) in the presence of the Zeeman field is the so-called helical state, which is characterized
by the phase modulation of the order parameter, but zero supercurrent density. In this work
we investigate the realization of the helical state in a hybrid system with ...
Added: November 24, 2022
Pudalov V., Сахин В. О., Куковицкий Е. Ф. et al., Письма в Журнал экспериментальной и теоретической физики 2022 Т. 115 № 4 С. 270–276
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 ...
Added: November 16, 2022
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
Kuntsevich A., Миньков Г. М., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 No. 19
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 from nontrivial. In this ...
Added: June 17, 2022
Yevtushenko O. M., Yudson V., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 104 Article 195414
Dynamical magnetic impurities (MI) are considered as a possible origin for suppression of the ballistic helical transport on edges of two-dimensional (2D) topological insulators. The MIs provide a spin-flip backscattering of itinerant helical electrons. Such a backscattering reduces the ballistic conductance if the exchange interaction between the MI and the electrons is anisotropic and the ...
Added: December 6, 2021
Fedotov N., Zaitsev-Zotov S., Physica Status Solidi - Rapid Research Letters 2019 Vol. 13 No. 5 Article 1800617
Topologically protected surface states of three-dimensional topological insulators provide a model framework for studying massless Dirac electrons in two dimensions. Usually a step on the surface of a topological insulator is treated as a scatterer for the Dirac electrons, and the study of its effect is focused on the interference of the incident and scattered ...
Added: October 29, 2021
Mazhorin G., Moskalenko I., Besedin I. et al., Physical Review A: Atomic, Molecular, and Optical physics 2022 Vol. 105 No. 3 Article 033519
We explore experimentally a quantum metamaterial based on a superconducting chip with 25 frequency-tunable transmon qubits coupled to a common coplanar resonator. The collective bright and dark modes are probed via the microwave response, i.e., by measuring the transmission amplitude of an external microwave signal. All qubits have individual control and readout lines. Their frequency ...
Added: October 29, 2021
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
Вальков В. В., Шустин М. С., Аксенов С. В. et al., Успехи физических наук 2022 Т. 192 № 1 С. 3–44
The review discusses properties of superconducting phases with a nontrivial topology and conditions for their implementation in condensed matter, criteria for the appearance of the Majorana-type elementary excitations in solids, as well as principles and experimental methods for identifying Majorana bound states (MBSs). Along with the well-known models of the Kitaev chain and superconducting nanowire ...
Added: March 16, 2021
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
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
Shchepetilnikov A., Khisameeva A., Nefyodov Y. A. et al., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 No. 12 Article 125425
The high-frequency conductivity of the two dimensional electron system formed at a ZnO/MgZnO heterojunction was investigated in the 4-18 GHz frequency range at high Landau level fillings and in the regime of both integer quantum Hall effect. The conductivity was probed by measuring the transmission of the broadband coplanar waveguide deposited on the sample surface. ...
Added: December 11, 2020
Shchepetilnikov A., Khisameeva A., Nefyodov Y. et al., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 No. 7 Article 075445
The high-frequency transport of a two-dimensional (2D) electron system was investigated by measuring the rf power transmitted through a pair of emitter/detector T-shaped antennas capacitively coupled to the 2D channel. The frequency range covered amounted to 10-100 MHz. The distinctive feature of such a setup is that neither were Ohmic contacts formed to the electron ...
Added: December 10, 2020
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
Piatrusha S. U., E.S. Tikhonov, Kvon Z. D. et al., Physical Review Letters 2019 Vol. 123 No. 5 P. 056801-1–056801-6
Recent topological band theory distinguishes electronic band insulators with respect to various symmetries and topological invariants, most commonly, the time reversal symmetry and the Z2 invariant. The interface of two topologically distinct insulators hosts a unique class of electronic states—the helical states, which shortcut the gapped bulk and exhibit spin-momentum locking. The magic and so ...
Added: July 30, 2019
Shapiro Dmitriy S., Feldman D. E., Mirlin A. et al., Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 95 No. 19 P. 195425-1–195425-10
We investigate the thermoelectric current and heat conductance in a chiral Josephson contact on a surface of a three-dimensional topological insulator, covered with superconducting and magnetic insulator films. The contact consists of two junctions of Majorana and Dirac channels next to two superconductors. Geometric asymmetry results in a supercurrent without a phase bias. The interference ...
Added: February 7, 2019