Fundamental insights to topological quantum materials: A real-space view of 13 cases by supersymmetry of valence bonds approach

This is a tutorial review of methods to braid non-Abelian anyons (Majorana zero-modes) in topological superconductors. That ``Holy Grail'' of topological quantum information processing has not yet been reached in the laboratory, but there now exists a variety of platforms in which one can search for the Majorana braiding statistics. After an introduction to the basic concepts of braiding we discuss how one might be able to braid immobile Majorana zero-modes, bound to the end points of a nanowire, by performing the exchange in parameter space, rather than in real space. We explain how Coulomb interaction can be used to both control and read out the braiding operation, even though Majorana zero-modes are charge neutral. We ask whether the fusion rule might provide for an easier pathway towards the demonstration of non-Abelian statistics. In the final part we discuss an approach to braiding in real space, rather than parameter space, using vortices injected into a chiral Majorana edge mode as ``flying qubits''.

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Angle-Resolved Photoemission Spectroscopy Study of Topological Quantum Materials

Annual Review of Materials Research ◽

10.1146/annurev-matsci-070218-121852 ◽

2020 ◽

Vol 50 (1) ◽

pp. 131-153

Author(s):

Chaofan Zhang ◽

Yiwei Li ◽

Ding Pei ◽

Zhongkai Liu ◽

Yulin Chen

Keyword(s):

Electronic Structures ◽

Photoemission Spectroscopy ◽

Topological Invariants ◽

New Materials ◽

Angle Resolved Photoemission Spectroscopy ◽

Topological Quantum ◽

Experimental Tool ◽

Weyl Semimetals ◽

Quantum Materials ◽

Physical Phenomena

The recently discovered topological quantum materials (TQMs) have electronic structures that can be characterized by certain topological invariants. In these novel materials, the unusual bulk and surface electrons not only give rise to many exotic physical phenomena but also foster potential new technological applications. To characterize the unusual electronic structures of these new materials, investigators have used angle-resolved photoemission spectroscopy (ARPES) as an effective experimental tool to directly visualize the unique bulk and surface electronic structures of TQMs. In this review, we first give a brief introduction of TQMs and ARPES, which is followed by examples of the application of ARPES to different TQMs ranging from topological insulators to Dirac and Weyl semimetals. We conclude with a brief perspective of the current development of ARPES and its potential application in the study of TQMs.

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Screening Topological Quantum Materials for Na-Ion Battery Cathode

ACS Materials Letters ◽

10.1021/acsmaterialslett.1c00545 ◽

2021 ◽

pp. 175-180

Author(s):

Wei Wu ◽

Qiang Sun

Keyword(s):

Topological Quantum ◽

Quantum Materials

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A topological semimetal Li2CrN2 sheet as a promising hydrogen storage material

Nanoscale ◽

10.1039/d0nr02180f ◽

2020 ◽

Vol 12 (22) ◽

pp. 12106-12113

Author(s):

Li-Juan Ma ◽

Qiang Sun

Keyword(s):

Hydrogen Storage ◽

Hydrogen Storage Material ◽

Storage Material ◽

Storage Performance ◽

Topological Quantum ◽

Topological Semimetal ◽

Quantum Materials ◽

Hydrogen Storage Performance ◽

First Time

The hydrogen storage performance of topological quantum materials is explored for the first time.

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Atomic-scale interface engineering of Majorana edge modes in a 2D magnet-superconductor hybrid system

Science Advances ◽

10.1126/sciadv.aav6600 ◽

2019 ◽

Vol 5 (7) ◽

pp. eaav6600 ◽

Cited By ~ 33

Author(s):

Alexandra Palacio-Morales ◽

Eric Mascot ◽

Sagen Cocklin ◽

Howon Kim ◽

Stephan Rachel ◽

...

Keyword(s):

Hybrid System ◽

Theoretical Calculations ◽

Real Space ◽

Scanning Tunneling Spectroscopy ◽

Atomic Scale ◽

Scanning Tunneling ◽

Edge States ◽

Interface Engineering ◽

New Paradigm ◽

Topological Quantum

Topological superconductors are predicted to harbor exotic boundary states—Majorana zero-energy modes—whose non-Abelian braiding statistics present a new paradigm for the realization of topological quantum computing. Using low-temperature scanning tunneling spectroscopy, here, we report on the direct real-space visualization of chiral Majorana edge states in a monolayer topological superconductor, a prototypical magnet-superconductor hybrid system composed of nanoscale Fe islands of monoatomic height on a Re(0001)-O(2 × 1) surface. In particular, we demonstrate that interface engineering by an atomically thin oxide layer is crucial for driving the hybrid system into a topologically nontrivial state as confirmed by theoretical calculations of the topological invariant, the Chern number.

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