Topological insulators and superconductors

XL Qi, SC Zhang - Reviews of modern physics, 2011 - APS
Topological insulators are new states of quantum matter which cannot be adiabatically
connected to conventional insulators and semiconductors. They are characterized by a full …

Odd-frequency superconducting pairing in one-dimensional systems

J Cayao, C Triola, AM Black-Schaffer - The European Physical Journal …, 2020 - Springer
Odd-frequency superconductivity represents a truly unconventional ordered state which, in
contrast to conventional superconductivity, exhibits pair correlations which are odd in …

Ballistic edge states in Bismuth nanowires revealed by SQUID interferometry

A Murani, A Kasumov, S Sengupta… - Nature …, 2017 - nature.com
The protection against backscattering provided by topology is a striking property. In two-
dimensional insulators, a consequence of this topological protection is the ballistic nature of …

Andreev Reflection of Helical Edge Modes in Quantum Spin Hall Insulator

I Knez, RR Du, G Sullivan - Physical review letters, 2012 - APS
We present an experimental study of SNS junctions, with N being a quantum spin Hall
insulator made of InAs/GaSb. A front gate is used to vary the Fermi level into the minigap …

Current–Phase Relation of a WTe2 Josephson Junction

M Endres, A Kononov, HS Arachchige, J Yan… - Nano Letters, 2023 - ACS Publications
When a topological insulator is incorporated into a Josephson junction, the system is
predicted to reveal the fractional Josephson effect with a 4π-periodic current–phase relation …

Odd-frequency superconducting pairing and subgap density of states at the edge of a two-dimensional topological insulator without magnetism

J Cayao, AM Black-Schaffer - Physical Review B, 2017 - APS
We investigate the emergence and consequences of odd-frequency spin-triplet s-wave
pairing in superconducting hybrid junctions at the edge of a two-dimensional topological …

Perfect Andreev reflection due to the Klein paradox in a topological superconducting state

S Lee, V Stanev, X Zhang, D Stasak, J Flowers… - Nature, 2019 - nature.com
In 1928, Dirac proposed a wave equation to describe relativistic electrons. Shortly
afterwards, Klein solved a simple potential step problem for the Dirac equation and …

Odd-frequency triplet superconductivity at the helical edge of a topological insulator

F Crépin, P Burset, B Trauzettel - Physical Review B, 2015 - APS
Nonlocal pairing processes at the edge of a two-dimensional topological insulator in
proximity to an s-wave superconductor are usually suppressed by helicity. However, the …

Phase-tunable electron transport assisted by odd-frequency Cooper pairs in topological Josephson junctions

J Cayao, P Dutta, P Burset, AM Black-Schaffer - Physical Review B, 2022 - APS
We consider a finite-size topological Josephson junction formed at the edge of a two-
dimensional topological insulator in proximity to conventional superconductors and study …

Spin‐helical transport in normal and superconducting topological insulators

G Tkachov, EM Hankiewicz - physica status solidi (b), 2013 - Wiley Online Library
In a topological insulator (TI) the character of electron transport varies from insulating in the
interior of the material to metallic near its surface. Unlike, however, ordinary metals …