scholarly journals Persistent current and zero-energy Majorana modes in a p -wave disordered superconducting ring

2017 ◽  
Vol 95 (15) ◽  
Author(s):  
Andrea Nava ◽  
Rosa Giuliano ◽  
Gabriele Campagnano ◽  
Domenico Giuliano
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aksel Kobiałka ◽  
Tadeusz Domański ◽  
Andrzej Ptok

Abstract Interplay between superconductivity, spin-orbit coupling and magnetic field can lead to realisation of the topologically non–trivial states which in finite one dimensional nanowires are manifested by emergence of a pair of zero-energy Majorana bound states. On the other hand, in two dimensional systems the chiral edge states can appear. We investigate novel properties of the bound states in a system of mixed dimensionality, composed of one-dimensional nanowire connected with two-dimensional plaquette. We study this system, assuming either its part or the entire structure to be in topologically non–trivial superconducting state. Our results show delocalisation of the Majorana modes, upon leaking from the nanowire to the plaquette with some tendency towards its corners.


2018 ◽  
Vol 9 ◽  
pp. 2171-2180 ◽  
Author(s):  
Samuel D Escribano ◽  
Alfredo Levy Yeyati ◽  
Elsa Prada

Majorana modes emerge in non-trivial topological phases at the edges of specific materials such as proximitized semiconducting nanowires under an external magnetic field. Ideally, they are non-local states that are charge-neutral superpositions of electrons and holes. However, in nanowires of realistic length their wave functions overlap and acquire a finite charge that makes them susceptible to interactions, specifically with the image charges that arise in the electrostatic environment. Considering a realistic three-dimensional model of the dielectric surroundings, here we show that, under certain circumstances, these interactions lead to a suppression of the Majorana oscillations predicted by simpler theoretical models, and to the formation of low-energy quantum-dot states that interact with the Majorana modes. Both features are observed in recent experiments on the detection of Majoranas and could thus help to properly characterize them.


Science ◽  
2020 ◽  
Vol 367 (6485) ◽  
pp. eaav3392 ◽  
Author(s):  
S. Vaitiekėnas ◽  
G. W. Winkler ◽  
B. van Heck ◽  
T. Karzig ◽  
M.-T. Deng ◽  
...  

Hybrid semiconductor-superconductor nanowires have emerged as a promising platform for realizing topological superconductivity (TSC). Here, we present a route to TSC using magnetic flux applied to a full superconducting shell surrounding a semiconducting nanowire core. Tunneling into the core reveals a hard induced gap near zero applied flux, corresponding to zero phase winding, and a gapped region with a discrete zero-energy state around one applied flux quantum, corresponding to 2π phase winding. Theoretical analysis indicates that the winding of the superconducting phase can induce a transition to a topological phase supporting Majorana zero modes. Measured Coulomb blockade peak spacing around one flux quantum shows a length dependence that is consistent with the existence of Majorana modes at the ends of the nanowire.


2013 ◽  
Vol 102 (5) ◽  
pp. 57002 ◽  
Author(s):  
B. Rosenstein ◽  
I. Shapiro ◽  
B. Ya. Shapiro
Keyword(s):  
P Wave ◽  

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
A. Bühler ◽  
N. Lang ◽  
C.V. Kraus ◽  
G. Möller ◽  
S.D. Huber ◽  
...  

2019 ◽  
Vol 7 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Ying Xing ◽  
Zhibin Shao ◽  
Jun Ge ◽  
Jiawei Luo ◽  
Jinhua Wang ◽  
...  

Abstract The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically non-trivial and host exotic Majorana modes. The layered material TaIrTe4 is a newly predicted time-reversal invariant type II Weyl semimetal with the minimum number of Weyl points. Here, we report the discovery of surface superconductivity in Weyl semimetal TaIrTe4. Our scanning tunneling microscopy/spectroscopy (STM/STS) visualizes Fermi arc surface states of TaIrTe4 that are consistent with the previous angle-resolved photoemission spectroscopy results. By a systematic study based on STS at ultralow temperature, we observe uniform superconducting gaps on the sample surface. The superconductivity is further confirmed by electrical transport measurements at ultralow temperature, with an onset transition temperature (Tc) up to 1.54 K being observed. The normalized upper critical field h*(T/Tc) behavior and the stability of the superconductivity against the ferromagnet indicate that the discovered superconductivity is unconventional with the p-wave pairing. The systematic STS, and thickness- and angular-dependent transport measurements reveal that the detected superconductivity is quasi-1D and occurs in the surface states. The discovery of the surface superconductivity in TaIrTe4 provides a new novel platform to explore topological superconductivity and Majorana modes.


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