Quenching the Anderson impurity model at finite temperature: Entanglement and bath dynamics using matrix product states

Abstract

We study the dynamics of the quenched Anderson model at finite temperature using matrix product states. Exploiting a chain mapping for the electron bath, we investigate the entanglement structure in the MPS for various orderings of the two chains, which emerge from the thermofield transformation employed to deal with nonzero temperature. We show that merging both chains can significantly lower the entanglement at finite temperatures as compared to an intuitive nearest-neighbor implementation of the Hamiltonian. Analyzing the population of the free bath modes -- possible when simulating the full dynamics of impurity plus bath -- we find clear signatures of the Kondo effect in the quench dynamics.