Mean-field calculation of the doping-iduced quantum spin Hall state to superconductor transiton
The mean-field theory and simulation result of the easy-plane t-λ model and the mean-field phase diagram are given in this paper.Two mean-field scenarios exist for doping the pure QSH state:1)a first-order QSH-SSC transition occurs in the weak interaction region;2)a continuous QSH to QSH-SSC co-existence transition followed by a first-order QSH-vanishing transition in the strong interaction region.The mean-field theory is found to capture features for symmetry-broken phases but give the wrong conclusion of QSH-SSC co-existence due to ignoring fluctuation.It is unable to characterize transitions with topological excitation.
quantum strongly correlationquantum spin Hall statesuperconductordopingmean-field calculation