Topological Josephson junction in transverse magnetic field
JETP Letters. 2022. Vol. 116. No. 12. P. 891-895.
Backens S., Shnirman A., Makhlin Y.
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 and yields methods to control the tunnel coupling between Majorana modes for quantum information processing applications.
Scanning tunneling microscopy of Bi2Te3 films prepared by pulsed laser deposition: from nanocrystalline structures to van der Waals epitaxy
, , et al., Surfaces and Interfaces 2022 Vol. 31 Article 102015
Bi2Te3 is a material with high efficiency of thermoelectric energy conversion. Recently, it was also recognized as a topological insulator, and is often used as the basis for creation of other types of topological matter. Pulsed laser deposition (PLD) is widely considered as a simple method for growing of multicomponent films, but not as a tool for van der Waals epitaxy. We ...
Added: October 15, 2022
, , 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
, 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
, , 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
, , 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
, , 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
, 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
Supercurrent vortices and Majorana zero modes induced by an in-plane Zeeman field on the surface of a three-dimensional topological insulator
, 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
, , 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
, , 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
, , , 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
Topology of the planar phase of superfluid 3He and bulk-boundary correspondence for three-dimensional topological superconductors
, , , 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
, , , 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
, , , 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
, , 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
, JETP Letters 2017 Vol. 106 No. 11 P. 739-742
We analyze the entanglement spectrum of superfluid phases of $^3$He, the 3D B-phase and the planar phase in two dimensions. We find explicitly the wave functions of the low-lying eigenstates, including Majorana zero modes, as well as the corresponding part of the spectrum of the entanglement Hamiltonian. ...
Added: November 23, 2017
, , , Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 104 No. 3 Article 035434
We consider an interferometer based on artificially induced topological superconductivity and chiral one-dimensional (1D) Majorana fermions. The (nontopological) superconducting island inducing the superconducting correlations in the topological substrate is assumed to be floating. This allows probing the physics of interfering Majorana modes via microwave response, i.e., the frequency-dependent impedance between the island and the earth. ...
Added: October 31, 2021
Long-range effect of a Zeeman field on the electric current through the helical metal-superconductor interface in an Andreev interferometer
, 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
, , 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
, , 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
, , 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
, , , The Density of Surface States in Weyl Semimetals / 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
, , , Scientific Reports 2019 Vol. 9 P. 1-8
The celebrated Jordan–Wigner transformation provides an efficient mapping between spin chains and fermionic systems in one dimension. Here we extend this spin–fermion mapping to arbitrary tree structures, which enables mapping between fermionic and spin systems with nearest-neighbor coupling. The mapping is achieved with the help of additional spins at the junctions between one-dimensional chains. This ...
Added: February 24, 2019
, , 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