Fig. 2
Bx − T phase diagram. a Phase diagram of Hamiltonian (1) for the set-up in Fig. 1a, in parameter space of in-plane magnetic field Bx and temperature T, in unit of Tc,0 (the superconducting transition temperature at Bx = 0). It comprises conventional Bardeen–Cooper–Schrieffer theory (BCS) phase (I), Fulde-Ferrell(FF) phase (II), Larkin–Ovchinnikov (LO) phase (III), and normal metal (IV). Parameters used here are m0 = −13.5 meV, m1 = 25 eV ⋅ Å2, v = 2.67 eV ⋅ Å, μ = 100 meV, which are probe for NbSe2/Bi2Se3/NbSe2, and UN0 = 0.27, and ωD = 20 meV, so that Tc,0 = 1.134 ωDexp(−1/UN0) = 0.5587 meV. b The critical field Bc/Tc,0 (transition between BCS and LO phase) as function of mF at fixed T/Tc,0 = 0.8. And Bc is reduced if the inter-layer tunneling is reduced. The inset figure shows vQ/Tc,0 as function of Bx/Tc,0 for different values of mF. The non-zero momentum Q develops when the phase transition between BCS and FF or LO occurs. Here, we only consider intra-layer superconducting pairing and ignore inter-layer interaction, namely V = 0
