Sauter-Schwinger like tunneling in tilted Bose-Hubbard lattices in the Mott phase

TL;DR

This paper explores quantum tunneling phenomena in tilted Bose-Hubbard lattices, revealing analogies to the Sauter-Schwinger effect and resonant tunneling behaviors, with implications for understanding particle-hole pair creation in quantum many-body systems.

Contribution

It introduces a quantitative analogy between tunneling in tilted Bose-Hubbard lattices and the Sauter-Schwinger effect, highlighting the role of quantum fluctuations beyond mean-field theory.

Findings

Quantum fluctuations enable particle-hole pair creation in the Mott phase.

An analogy to the Sauter-Schwinger effect is established for small potential gradients.

Resonant tunneling related to Bloch oscillations occurs at large tilts.

Abstract

We study the Mott phase of the Bose-Hubbard model on a tilted lattice. On the (Gutzwiller) mean-field level, the tilt has no effect -- but quantum fluctuations entail particle-hole pair creation via tunneling. For small potential gradients (long-wavelength limit), we derive a quantitative analogy to the Sauter-Schwinger effect, i.e., electron-positron pair creation out of the vacuum by an electric field. For large tilts, we obtain resonant tunneling related to Bloch oscillations.