Surrogate model solver for impurity-induced superconducting subgap states
Abstract
A simple impurity solver is shown to capture the impurity-induced superconducting subgap states in quantitative agreement with the numerical renormalization group and quantum Monte-Carlo simulations. The solver is based on the exact diagonalization of a single-impurity Anderson model with discretized superconducting reservoirs including only a small number of effective levels. Their energies and couplings to the impurity -level are chosen so as to best reproduce the Matsubara frequency dependence of the hybridization function. We provide a number of critical benchmarks and demonstrate the solvers efficiency in combination with the reduced basis method [Phys. Rev. B 107, 144503 (2023)] by calculating the phase diagram for an interacting three-terminal junction.
Keywords
Cite
@article{arxiv.2307.11646,
title = {Surrogate model solver for impurity-induced superconducting subgap states},
author = {Virgil V. Baran and Emil J. P. Frost and Jens Paaske},
journal= {arXiv preprint arXiv:2307.11646},
year = {2023}
}
Comments
19 pages, 20 figures; v2: new results on the phase diagram of a finite-gap interacting topological three-terminal Josephson junction