Off-resonant many-body quantum carpets in strongly tilted optical lattices

TL;DR

This paper explores off-resonant many-body quantum dynamics in strongly tilted optical lattices, revealing ballistic dipole wave propagation, quantum carpet patterns, and boundary effects in a many-body Wannier-Stark system.

Contribution

It introduces an effective Hamiltonian capturing second order tunneling, demonstrating quantum carpet formation and boundary effects in many-body tilted lattice systems.

Findings

Ballistic dipole wave propagation observed

Quantum carpet interference patterns identified

Wavefunction diffusion characterized after first reflection

Abstract

An unit filling Bose-Hubbard Hamilonian embedded in strong Stark field is studied in the off-resonant regime inhibiting single and many-particle first order tunneling resonances. We investigate the occurrence of coherent dipole wave-like propagation along of an optical lattice by means of an effective Hamiltonian accounting for second order tunneling processes. It is shown that dipole wavefunction evolution in the short-time limit is ballistic and that finite size effects induce dynamical self-interference patterns known as quantum carperts. We also present the effects of the border right after the first reflection showing that the wavefunction diffuses normally with the variance changing linearly in time. This work extends the rich physical phenomenology of the tilted one dimensional lattice systems in a scenario of many interacting quantum particles, the so-called many-body Wannier-Stark system.