Sharma, Vaibhav - Cornell University

Condensed bosons get squeezed and enter the lowest landau level in a rotating frame

Motivated by a recent experiment, we model interacting bosons in a harmonic trap with a rotating elliptical deformation. The system Hamiltonian in the rotating frame is equivalent to the Hamiltonian for a charged particle in a uniform magnetic field.  Bosons condensed in the lowest landau level can serve as a route to study fractional quantum hall physics and strong interaction effects in a flat band with neutral cold atoms. We show how bosons in this situation can dynamically enter the lowest landau level. We use a time-dependent variational wavefunction approach to efficiently model the dynamics. We find that our approach reliably captures a dynamical squeezing of the Bose gas observed in the experiment. We also find that the bosons macroscopically occupy the lowest landau level only if the elliptical deformation is switched off slowly over a particular timescale. We estimate this timescale and provide an intuitive understanding of the phenomena.