Eur. Phys. J. B (2017) 90: 131
https://doi.org/10.1140/epjb/e2017-80238-9

Regular Article

Pairing in doped inversion-symmetric Weyl semimetals: a finite temperature analysis from Thouless criterion

Department of Physics, Yancheng Institute of Technology, Yancheng 224051, P.R. China

^a e-mail: hbb4236@ycit.edu.cn

Received: 23 April 2017
Published online: 10 July 2017

Abstract

In doped Weyl semimetal with inversion symmetry, the two pairing states, i.e., the zero momentum BCS pairing and the finite momentum Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) pairing are possible in principle. In this paper we use the standard Thouless criterion for the onset of pairings to investigate the leading pairing instability at the finite temperature. Our results suggest that both BCS and FFLO instabilities are possible depending on the on-site attractive interaction. The competition between the BCS pairing and FFLO pairing is driven by the mutual suppression between density of state near the Fermi surface and finite energy band structure in the whole Brillouin zone. For small and intermediate interaction, the former dominates and supports BCS pairing, while for strong interaction, the latter wins and favors FFLO pairing. We expect our results at the finite temperature can provide some important message to identify the true ground state.