Engineering fidelity echoes in Bose-Hubbard Hamiltonians

¹  Wesleyan University, Department of Physics - 265 Church St., Middletown, CT 06459, USA
²  MPI for Dynamics and Self-Organization - Bunsenstraße 10, D-37073 Göttingen, Germany
³  Fakultät für Physik, Universität Göttingen - Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany

Received: 20 February 2007
Accepted: 20 April 2007

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.