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.
Makhlin Y., Silaev M., Volovik G.
We provide topological classification of possible phases with the symmetry of the planar phase of superfluid
, , , 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., Physical Review Letters 2015 Vol. 115 P. 165304
We report the first observation of the polar phase of superfluid 3He. This phase appears in 3He confined in a new type of aerogel with a nearly parallel arrangement of strands which play the role of ordered impurities. Our experiments qualitatively agree with theoretical predictions and suggest that in other systems with unconventional Cooper pairing ...
Added: December 26, 2017
, , 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
, , 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
, 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
, , , Nanoscale Research Letters 2012 Vol. 7 No. 163 P. 1-10
We study collective excitations in a helical electron liquid on a surface of three-dimensional topological insulator. Electron in helical liquid obeys Dirac-like equation for massless particles and direction of its spin is strictly determined by its momentum. Due to this spin-momentum locking, collective excitations in the system manifest themselves as coupled charge- and spin-density waves. ...
Added: March 14, 2013
Half-quantum vortices and walls bounded by strings in the polar-distorted phases of topological superfluid 3He
, , et al., Nature Communications 2019 Vol. 10 P. 237-1-237-8
Symmetries of the physical world have guided formulation of fundamental laws, including relativistic quantum field theory and understanding of possible states of matter. Topological defects (TDs) often control the universal behavior of macroscopic quantum systems, while topology and broken symmetries determine allowed TDs. Taking advantage of the symmetry-breaking patterns in the phase diagram of nanoconfined ...
Added: January 22, 2019
, , et al., Physical Review Letters 2016 Vol. 117 No. 25 P. 255301-1-255301-6
One of the most sought-after objects in topological quantum-matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid 3He−A but have never been resolved there. Here we report an observation of half-quantum vortices (HQVs) in the polar phase of superfluid 3He. The vortices are created with rotation or by ...
Added: October 24, 2017
, , 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
, , et al., Physical Review Letters 2018 Vol. 121 No. 2 P. 025303-1-025303-6
The polar phase of 3He, which is topological spin-triplet superfluid with the Dirac nodal line in the spectrum of Bogoliubov quasiparticles, has been recently stabilized in a nanoconfined geometry. We pump magnetic excitations (magnons) into the sample of polar phase and observe how they form a Bose-Einstein condensate, revealed by coherent precession of the magnetization of ...
Added: November 23, 2018
, , , Physical Review B: Condensed Matter and Materials Physics 2012 Vol. 86 No. 11-5436 P. 1-9
We consider the pairing of massless Dirac electrons and holes located on opposite surfaces of thin films of “strong” three-dimensional topological insulators. Such pairing is predicted to give rise to a topological exciton condensate with unusual properties. We estimate the quantitatively achievable critical temperature of the pairing while taking into account the self-consistent screening of ...
Added: March 14, 2013
, , et al., JETP Letters 2017 Vol. 105 No. 8 P. 489-490
We study the effect of the Fermi surface anisotropy (hexagonal warping) on the superconducting pair potential, induced in a three-dimensional topological insulator (TI) by proximity with an s-wave superconductor (S) in presence of a magnetic moment of a nearby ferromagnetic insulator (FI). In the previous studies similar problem was treated with a simplified Hamiltonian, describing ...
Added: April 7, 2017
Experimental Observation of Bound States of 2D Dirac Electrons at Surface Steps of the Topological Insulator Bi2Se3
, , 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
, , et al., Physical Review B: Condensed Matter and Materials Physics 2016 Vol. 94 No. 23 P. 235401-1-235401-8
Bismuth chalcogenides are the most studied 3D topological insulators. As a rule, at low temperatures, thin films of these materials demonstrate positive magnetoresistance due to weak antilocalization. Weak antilocalization should lead to resistivity decrease at low temperatures; in experiments, however, resistivity grows as temperature decreases. From transport measurements for several thin films ( with various ...
Added: February 24, 2018
, , 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
, , 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
, , , Physical Review Letters 2018 Vol. 120 No. 7 P. 075301-1-075301-5
We report results of experiments with superfluid 3He confined in aerogels with parallel strands which lead to anisotropic scattering of 3He quasiparticles. We vary boundary conditions for the scattering by covering the strands with different numbers of atomic 4He layers and observe that the superfluid phase diagram and the nature of superfluid phases strongly depend on the coverage. We assume the ...
Added: February 21, 2018
, , 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
, , , JETP Letters 2016 Vol. 103 P. 643-647
We report results of low frequency nuclear magnetic resonance (NMR) experiments in the superfluid polar phase of 3He, which is stabilized by a new type of “nematic” aerogel—nafen. We have found that an interaction between transverse and longitudinal NMR modes may essentially influence the spin dynamics. Theoretical formulas for NMR resonant frequencies are derived and applied ...
Added: January 22, 2018
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
, , , 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
, , et al., Успехи физических наук 2022 Т. 192 № 1 С. 3-148
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
, , 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