Open AccessSpontaneous magnetic field and odd-frequency pairing state in multiband superconductors
Author(s) -
Yanyan Zhang,
Jia-Lin Chen,
Guo-Qiao Zha,
ShiPing Zhou
Publication year - 2019
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.68.20190445
Subject(s) - pairing , physics , condensed matter physics , parity (physics) , singlet state , superconductivity , t symmetry , triplet state , spin (aerodynamics) , phase diagram , coupling (piping) , quantum mechanics , phase (matter) , excited state , materials science , metallurgy , thermodynamics
We investigate the interband coupling induced odd-frequency pairing state by solving the microscopic Ginzburg-Landau model for the two band superconductor magnesium diboride (MgB 2 ). It is found that the interband coupling can induce a new domain structure and a heliacal spontaneous magnetic vortex-antivortex pair around the cyclical domain wall, which breaks down spin-rotational symmetry and supports a time-reversal violating bound state, allowing the coexistence of spin-singlet and spin-triplet state close to the spontaneous vortex core. The odd-frequency spin-triplet even parity pairing state occurs since a successive operation in the orbital parity (P) and the time-reversal (T) obeys PT = + 1(–1) for spin-singlet (spin-triplet) pairing amplitude. A general phase diagram is presented.