Topological quantum phase transitions in the spin–singlet superconductor with Rashba and Dresselhaus (110) spin–orbit couplings

Journal Article · Wed Oct 15 00:00:00 EDT 2014 · Annals of Physics (New York)

DOI:https://doi.org/10.1016/J.AOP.2014.06.009· OSTI ID:22403407

You, Jia-Bin ^[1]; Chan, A. H. ^[2]; Vedral, Vlatko ^[1]

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1. Centre for Quantum Technologies, National University of Singapore, 117543 (Singapore)
2. Department of Physics, National University of Singapore, 117542 (Singapore)

We examine the topological properties of a spin–singlet superconductor with Rashba and Dresselhaus (110) spin–orbit couplings. We demonstrate that there are several topological invariants in the Bogoliubov–de Gennes (BdG) Hamiltonian by symmetry analysis. In particular, the Pfaffian invariant P for the particle–hole symmetry can be used to demonstrate all the possible phase diagrams of the BdG Hamiltonian. We find that the edge spectrum is either Dirac cone or flat band which supports the emergence of the Majorana fermion in this system. For the Majorana flat bands, an edge index, namely the Pfaffian invariant P(k{sub y}) or the winding number W(k{sub y}), is needed to make them topologically stable. These edge indices can also be used in determining the location of the Majorana flat bands. - Highlights: • Majorana fermion can emerge in the spin–orbit coupled singlet superconductor. • Pfaffian invariant and 1D winding number can be used to identify the nontrivial topological phase where Majorana flat band exists. • All the possible phase diagrams in the spin–orbit coupled singlet superconductor are demonstrated. • Majorana flat band only exists in the y direction in our model. • Majorana flat band has a significant experimental signature in the tunneling conductance measurement.

• OSTI ID: 22403407
• Journal Information: Annals of Physics (New York), Vol. 349; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-4916
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FERMIONS
HAMILTONIANS
L-S COUPLING
MAJORANA THEORY
PARTICLE-HOLE MODEL
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
QUANTUM STATES
SPIN
SUPERCONDUCTORS
TOPOLOGY
TUNNEL EFFECT