2016/12/20 by Luyang Wang
Materials Science · Physics and Astronomy · #Coupling (piping) #Density of states #Dimensionless quantity #Fermi Gamma-ray Space Telescope #Fermi energy #Fermi gas #Instability #Momentum (technical analysis) #Organic and Molecular Conductors Research #Rare-earth and actinide compounds #Superconductivity #Topological Materials and Phenomena #Zeeman effect #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/2399-6528/aa8215
published as J. Phys. Commun. 1, 011001 (2017) · 5 pages + supplemental material
arxiv created 2016/12/20 · openalex created_date 2017/01/26 · openalex publication_date 2017/09/01 · arxiv updated 2017/09/15 · openalex updated_date 2026/08/05
We study the superconducting instability and the resulting superconducting states in a two-dimensional repulsive Fermi gas with Rashba spin–orbit coupling at low electron density (namely the Fermi energy E F is lower than the energy E R of the Dirac point induced by Rashba coupling). We find that superconductivity is enhanced as the dimensionless Fermi energy ( ) decreases, due to two reasons. First, the density of states at increases as . Second, the particle–hole bubble becomes more anisotropic, resulting in an increasing effective attraction. The superconducting state is always in the total angular momentum (or ) channel with Chern number C = 4 (or ), breaking time reversal symmetry spontaneously. Although a putative Leggett mode is expected due to the two-gap nature of the superconductivity, we find that it is always damped. More importantly, once a sufficiently large Zeeman coupling is applied to the superconducting state, the Chern number can be tuned to be ±1 and Majorana zero modes exist in the vortex cores.