Quantum switching at a mean-field instability of a Bose-Einstein condensate in an optical lattice

Abstract

It is shown that bifurcations of the mean-field dynamics of a Bose-Einstein condensate can be related with the quantum phase transitions of the original many-body system. As an example we explore the intra-band tunneling in the two-dimensional optical lattice. Such a system allows for easy control by the lattice depth as well as for macroscopic visualization of the phase transition. The system manifests switching between two selftrapping states or from a selftrapping state to a superposition of the macroscopically populated selftrapping states with the step-like variation of the control parameter about the bifurcation point. We have also observed the magnification of the microscopic difference between the even and odd number of atoms to a macroscopically distinguishable dynamics of the system.

4 pages, 3 figures (2 in color)

References in corpus (3)

• Differences between mean-field dynamics and N-particle quantum dynamics as a signature of entanglement
• Nonlinear tunneling of BEC in an optical lattice: signatures of quantum collapse and revival
• Nonlinear intraband tunneling of BEC in a cubic three-dimensional lattice

Cited by in corpus (5)

• Excited-state quantum phase transitions
• Quantum phase transitions of atom-molecule Bose mixtures in a double-well potential
• State diagram and the phase transition of $p$-bosons in a square bi-partite optical lattice
• Excited-state quantum phase transitions in constrained systems
• Superfluid Oscillator Circuit with Quantum Current Regulator