Evolution of the Andreev bands in the half-filled superconducting periodic Anderson model

We employ the periodic Anderson model with superconducting correlations in the conduction band at half filling to study the behavior of the in-gap bands in a heterostructure consisting of a molecular layer deposited on the surface of a conventional superconductor. We use the dynamical mean-field theory to map the lattice model on the superconducting single impurity model with self-consistently determined bath and use the continuous-time hybridization expansion (CT-HYB) quantum Monte Carlo and the iterative perturbation theory (IPT) as solvers for the impurity problem. We present phase diagrams for square and triangular lattice that both show two superconducting phases that differ by the sign of the induced pairing, in analogy to the 0 and pi phases of the superconducting single impurity Anderson model and discuss the evolution of the spectral function in the vicinity of the transition. We also discuss the failure of the IPT for superconducting models with spinful ground state and the behavior of the average expansion order of the CT-HYB simulation.

Automated summary

In this study, the behavior of in-gap bands in a heterostructure was investigated using the periodic Anderson model with superconducting correlations, and the lattice model was mapped onto the superconducting single impurity model using dynamical mean-field theory. Two distinct superconducting phases were observed in phase diagrams, each corresponding to different induced pairing signs, and the evolution of the spectral function near the transition was discussed. Additionally, the failure of iterative perturbation theory for superconducting models with spinful ground state and the behavior of the average expansion order in the continuous-time hybridization expansion simulation were explored.