Engineering fidelity echoes in Bose-Hubbard Hamiltonians

TL;DR

This paper investigates fidelity decay in Bose-Hubbard systems, revealing persistent echoes linked to energy landscape structures, and highlights the roles of classical effects and self-trapping phenomena across different perturbation regimes.

Contribution

It introduces an analysis of fidelity echoes in Bose-Hubbard models, combining quantum and classical perspectives, and employs an improved random matrix approach for description.

Findings

Echoes linked to non-universal energy landscape structures persist in quantum regimes.

Classical self-trapping phenomena influence echo efficiency at strong perturbations.

An improved random matrix model effectively describes fidelity decay behaviors.

Abstract

We analyze the fidelity decay for a system of interacting bosons described by a Bose-Hubbard Hamiltonian. We find echoes associated with "non-universal" structures that dominate the energy landscape of the perturbation operator. Despite their classical origin, these echoes persist deep into the quantum (perturbative) regime and can be described by an improved random matrix modeling. In the opposite limit of strong perturbations (and high enough energies), classical considerations reveal the importance of self-trapping phenomena in the echo efficiency.