scholarly journals Topological superconductors in one-dimensional mosaic lattices

Author(s):  
Qi-Bo Zeng ◽  
Rong Lü ◽  
Li You
Author(s):  
Niccolò Traverso Ziani ◽  
Lucia Vigliotti ◽  
Matteo Carrega ◽  
Fabio Cavaliere

Majorana bound states in topological superconductors have attracted intense research activity in view of applications in topological quantum computation. However, they are not the only example of topological bound states that can occur in such systems. We here study a model in which both Majorana and Tamm bound states compete. We show both numerically and analytically that, surprisingly, the Tamm state remains partially localized even when the spectrum becomes gapless. Despite this fact, we demonstrate that the Majorana polarization shows a clear transition between the two regimes.


2020 ◽  
Vol 101 (8) ◽  
Author(s):  
P. Fromholz ◽  
G. Magnifico ◽  
V. Vitale ◽  
T. Mendes-Santos ◽  
M. Dalmonte

2013 ◽  
Vol 87 (6) ◽  
Author(s):  
David Pekker ◽  
Chang-Yu Hou ◽  
Doron L. Bergman ◽  
Sam Goldberg ◽  
İnanç Adagideli ◽  
...  

Science ◽  
2017 ◽  
Vol 358 (6364) ◽  
pp. 772-776 ◽  
Author(s):  
Sangjun Jeon ◽  
Yonglong Xie ◽  
Jian Li ◽  
Zhijun Wang ◽  
B. Andrei Bernevig ◽  
...  

One-dimensional topological superconductors host Majorana zero modes (MZMs), the nonlocal property of which could be exploited for quantum computing applications. We use spin-polarized scanning tunneling microscopy to show that MZMs realized in self-assembled Fe chains on the surface of Pb have a spin polarization that exceeds that stemming from the magnetism of these chains. This feature, captured by our model calculations, is a direct consequence of the nonlocality of the Hilbert space of MZMs emerging from a topological band structure. Our study establishes spin-polarization measurements as a diagnostic tool to distinguish topological MZMs from trivial in-gap states of a superconductor.


2019 ◽  
Vol 6 (5) ◽  
Author(s):  
Fernando de Juan ◽  
Jens H Bardarson ◽  
Roni Ilan

Among the different platforms to engineer Majorana fermions in one-dimensional topological superconductors, topological insulator nanowires remain a promising option. Threading an odd number of flux quanta through these wires induces an odd number of surface channels, which can then be gapped with proximity induced pairing. Because of the flux and depending on energetics, the phase of this surface pairing may or may not wind around the wire in the form of a vortex. Here we show that for wires with discrete rotational symmetry, this vortex is necessary to produce a fully gapped topological superconductor with localized Majorana end states. Without a vortex the proximitized wire remains gapless, and it is only if the symmetry is broken by disorder that a gap develops, which is much smaller than the one obtained with a vortex. These results are explained with the help of a continuum model and validated numerically with a tight binding model, and highlight the benefit of a vortex for reliable use of Majorana fermions in this platform.


Author(s):  
Niels Breckwoldt ◽  
Thore Posske ◽  
Michael Thorwart

Abstract Braiding Majorana zero-modes around each other is a promising route towards topological quantum computing. Yet, two competing maxims emerge when implementing Majorana braiding in real systems: On the one hand, perfect braiding should be conducted adiabatically slowly to avoid non-topological errors. On the other hand, braiding must be conducted fast such that decoherence effects introduced by the environment are negligible, which are generally unavoidable in finite-size systems. This competition results in an intermediate time scale for Majorana braiding that is optimal, but generally not error-free. Here, we calculate this intermediate time scale for a T-junction of short one-dimensional topological superconductors coupled to a bosonic bath that generates fluctuations in the local electric potential, which stem from, e.g., environmental photons or phonons of the substrate. We thereby obtain boundaries for the speed of Majorana braiding with a predetermined gate fidelity. Our results emphasize the general susceptibility of Majorana-based information storage in finite-size systems and can serve as a guide for determining the optimal braiding times in future experiments.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
James Jun He ◽  
Tian Liang ◽  
Yukio Tanaka ◽  
Naoto Nagaosa

AbstractMajorana fermions, as electronic quasi-particle modes in solid states, have been under the focus of research due to their exotic physical properties. While the evidence of Majorana fermions as zero-dimensional bound states has been well established, the existence of one-dimensional Majorana modes is still under debate. The main reason is that the current theoretical proposals of platforms supporting such states are very challenging experimentally. Here, we propose a method to create two-dimensional topological superconductors with a heterostructure of ferromagnet, topological insulator thin film and superconductor. We show that such a system supports one-dimensional chiral Majorana edge modes in a wide range of parameters which is readily achievable in experiments. We further propose a new transport measurement to detect these modes.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Yang Lin ◽  
Weichang Hao ◽  
Mei Wang ◽  
Jianqiang Qian ◽  
Huaiming Guo

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