Nonlinear tunneling of BEC in an optical lattice: signatures of quantum collapse and revival

TL;DR

This paper explores the quantum tunneling behavior of Bose-Einstein condensates in optical lattices, revealing observable quantum collapse and revival phenomena and connecting quantum and mean-field descriptions.

Contribution

It demonstrates the occurrence of quantum collapse and revival in a fully quantum model and links it to mean-field theory via the WKB approximation.

Findings

Quantum collapse and revival are observable in the quantum tunneling of BECs.

Two distinct tunneling regimes are identified and characterized.

The dependence of collapse and revival on atom number is analyzed.

Abstract

Quantum theory of the intraband resonant tunneling of a Bose-Einstein condensate loaded in a twodimensional optical lattice is considered. It is shown that the phenomena of quantum collapse and revival can be observed in the fully quantum problem. The mean-field limit of the theory is analyzed using the WKB approximation for discrete equations, establishing in this way a direct connection between the two approaches conventionally used in very different physical contexts. More specifically we show that there exist two different regimes of tunneling and study dependence of quantum collapse and revival on the number of condensed atoms.