Wei Zheng (郑炜)
Cambridge University (UK)
Dr. Wei Zheng received his Ph.D in physics from the School of Physics and Engineering, Sun Yat-sen University. He is currently a postdoc working in the T.C.M Group, Cavendish Laboratory, Cambridge University (UK). Dr. Wei's research is focused on the theory of cold atom physics including: 1) Quantum gases in the synthetic gauge field; 2) Quantum gases with internal degrees of freedom; 3) Topological states in the cold atom system; 4) Strongly interacting Fermi gases nearby Feshbach resonance; 5) Non-equilibrium phenomena in cold atom system.
2017-12-11 - 2017-12-12 Office No:
Inviter: Prof. Xiaoling Cui
Contact Person: Contact Number:
|Talk Title: Particle transport in Dynamical Optical lattices
Talk Place: M-253
Talk Time: 11-Dec-2017 10:00 am
One of the most interesting directions of research in coherent quantum systems concerns the collective dynamics of coupled atom-photon ensembles. Such situations arise for cold atomic gases in optical cavities or waveguides, where strong coupling between atomic motion and a photon field can be achieved. Coupling cold atoms even to a single cavity mode can dramatically change the steady state of the atomic gas and lead to interesting nonequilibrium dynamics. In this talk, I will introduce our recent work on particle transport in dynamical optical lattices. The dynamical lattice is chosen to have a period that is incommensurate with that of an underlying static lattice. This dynamical lattice can be regarded as a dynamical version of the Aubry-Andr'e model, which can cause localization of single-particle wave functions. We show that atomic wave packets in this dynamical lattice generically spread via anomalous diffusion, which can be tuned between super-diffusive and sub-diffusive regimes. To understand this anomalous diffusion, we use the quantum trajectory picture to map the dynamics into a L'evy walk with rests.