Nonmetallic thermal transport in low-dimensional proximity structures with partially preserved time-reversal symmetry in a magnetic field

Tkachov, G.

doi:10.1016/j.physc.2004.10.015

Cited by 15 publications

(30 citation statements)

References 67 publications

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“…Tunneling into these supercurrents shifts the momentum of the quasiparticles and ultimately their energy. Since this only occurs forsuperconducting quasiparticles, the observation of the Doppler effect confirms the presence of Andreev reflection, as established in numerous theoretical and experimental works [44,45,[47][48][49][50][51][52][53][54][55][56][57].…”

Section: Methodssupporting

confidence: 77%

Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures

Zareapour¹,

Hayat²,

Zhao³

et al. 2017

New J. Phys.

4
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4
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We address the controversy over the proximity effect between topological materials and high-T c superconductors. Junctions are produced between Bi 2 Sr 2 CaCu 2 O d + 8and materials with different Fermi surfaces (Bi 2 Te 3 andgraphite). Both cases reveal tunneling spectra that areconsistent with Andreev reflection. This is confirmed by a magnetic field that shifts features via the Doppler effect. This is modeled with a single parameter that accounts for tunneling into a screening supercurrent. Thus the tunneling involves Cooper pairs crossing the heterostructure, showing thatthe Fermi surface mismatch does not hinder the ability to form transparent interfaces, which is accounted for by the extended Brillouin zone and different lattice symmetries.

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Section: Methodssupporting
confidence: 77%

Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures
Zareapour¹,
Hayat²,
Zhao³
et al. 2017
New J. Phys.
4
2
4
0
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“…Unlike the previous work (e.g., Refs. [22,23]), we choose the geometry in which the phase gradient is perpendicular to the conducting channel and switches the sign between the superconducting banks. In this case, the magnetic field produces a phase twist across the junction, creating Andreev bound states in the absence of any external phase bias.…”

Section: Discussionmentioning
confidence: 99%

Soliton defects and topological ${4\pi}$ -periodic superconductivity from an orbital magnetic field effect in edge Josephson junctions
Tkachov
¹

2019
J. Phys.: Condens. Matter
8
2
12
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Recently, much research has been dedicated to understanding topological superconductivity and Majorana zero modes induced by a magnetic field in hybrid proximity structures. This paper proposes a realization of topological superconductivity in a short Josephson junction at an edge of a 2D topological insulator subject to a perpendicular magnetic field. The magnetic field effect is entirely orbital, coming from a gradient of the order parameter phase at the edge, which results in a soliton defect at the junction with a pair of gapless Andreev bound states. The latter are reducible to Majorana zero modes by a unitary rotation and protected by a chiral symmetry. Furthermore, both ground state and excitations are quasiperiodic in the magnetic flux enclosed in the junction, with the period equal to the double flux quantum 2Φ 0 = h/e. This behaviour follows from the gauge invariance of the 4π -phase periodicity of the Majorana states and manifests itself as 2Φ 0 -spaced magnetic oscillations of the critical current. Another proposed observable is a persistent current occurring in the absence of an external phase bias. Beside the oscillations, it shows a sign reversal prompted by the neutral Majorana zero modes. These findings offer the possibility to access topological superconductivity through low-field dc magnetotransport measurements.

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“…On the other hand, microscopic approaches (e.g., McMillan's model) 26 allow for a more general description of the proximity effect in terms of the Green functions of the S. We employ a microscopic model close in spirit to McMillan's 26 and its adaptations to various low-dimensional systems (see, e.g., Refs. 7,14,17,19,25,[27][28][29][30][31][32]. Without losing essential physics we treat both the TI surface state and the S film as two-dimensional (2D) systems in which electronic states are labeled by the in-plane momentum k. Assuming tunneling coupling between the systems, we can write the Hamiltonian of such a bilayer as (particle-hole) representation:…”

Section: Introductionmentioning
confidence: 99%

Suppression of surfacep-wave superconductivity in disordered topological insulators
Tkachov
¹

2013
Phys. Rev. B
Self Cite
39
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58
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The paper proposes a self-consistent Green function description of the induced surface superconductivity in a disordered three-dimensional topological insulator (TI) coupled to an s-wave superconductor. We recover earlier results regarding the induced spin-triplet p-wave pairing, showing that a mixture of pand s-wave pair correlations appears as a result of broken spin-rotation symmetry on the helical surface of the TI. Unlike the s-wave pairing, the p-wave component is found to be suppressed in dirty TIs in which the elastic mean-free path is much smaller than the superconducting coherence length. The suppression is due to the generic nonlocality of the spin-triplet correlations, which makes them strongly dependent on the mean-free path in a disordered system. In dirty TIs the induced superconductivity is predicted to be predominantly s-wave like. In cleaner TIs, however, the p-wave component may reach a magnitude comparable to (but not larger than) the s-wave pairing.

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Nonmetallic thermal transport in low-dimensional proximity structures with partially preserved time-reversal symmetry in a magnetic field

Cited by 15 publications

References 67 publications

Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures

Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures

Soliton defects and topological ${4\pi}$ -periodic superconductivity from an orbital magnetic field effect in edge Josephson junctions

Suppression of surfacep-wave superconductivity in disordered topological insulators

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Nonmetallic thermal transport in low-dimensional proximity structures with partially preserved time-reversal symmetry in a magnetic field

Cited by 15 publications

References 67 publications

Andreev reflection without Fermi surface alignment in high-Tcvan der Waals heterostructures

Andreev reflection without Fermi surface alignment in high-Tcvan der Waals heterostructures

Soliton defects and topological ${4\pi}$ -periodic superconductivity from an orbital magnetic field effect in edge Josephson junctions

Suppression of surfacep-wave superconductivity in disordered topological insulators

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Product

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Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures

Andreev reflection without Fermi surface alignment in high-T_cvan der Waals heterostructures