arXiv subjects

Daw-wei Wang

Publications and source records attributed to Daw-wei Wang.

3 recordsLinked to original sources

arXiv2019

Controllable splitting dynamics of a doubly quantized vortex in a rotating ring-shaped condensate

We study the dynamics of a doubly quantized vortex (DQV), created by releasing a ring-shaped Bose-Einstein condensate with quantized circulation into harmonic potential traps. It is shown that a DQV can be generated and exists stably in the middle of the ring-shaped condensate with the initial circulation $s = 2$ after released into the rotationally symmetric trap potential. For an asymmetric trap with a small degree of anisotropy the DQV initially splits into two singly quantized vortices and revives again but eventually evolves into two unit vortices due to the dynamic instability. For the degree of anisotropy above a critical value, the DQV is extremely unstably and decays rapidly into two singlet vortices. The geometry-dependent lifetime of the DQV and vortex-induced excitations are also discussed intensively.

cond-mat.quant-gas↗

arXiv2016

Spin-orbit-coupling-induced magnetic heterostructure in the bilayer Bose-Hubbard system

We investigate magnetic phase in the bilayer system of ultra-cold bosons in an optical lattice, which is involved with Raman-induced spin-orbit (SO) coupling and laser-assisted interlayer tunneling. It is shown that there exit a rich of spin textures such as hetero ferromagnet, heterochiral magnet, chiral magnet with interlayer antiferromagnet. In particular, heterochiral magnet induced by SO coupling occurs extremely rarely in real solid-state materials. We present detailed experimental setup of realizing such a model in cold atom system.

cond-mat.quant-gas↗

arXiv2015

Nonadiabatic multichannel dynamics of a spin-orbit coupled condensate

We investigate the nonadiabatic dynamics of a driven spin-orbit-coupled Bose-Einstein condensate in both weak and strong driven force. It is shown that the standard Landau-Zener (LZ) tunneling fails in the regime of weak driven force and/or strong spin-orbital coupling, where the full nonadiabatic dynamics requires a new mechanism through multichannel effects. Beyond the semiclassical approach, our numerical and analytical results show an oscillating power-law decay in the quantum limit, different from the exponential decay in the semiclassical limit of the LZ effect. Furthermore, the condensate density profile is found to be dynamically fragmented by the multichannel effects and enhanced by interaction effects. Our work therefore provides a complete picture to understand the nonadiabatic dynamics of a spin-orbit coupled condensate, including various range of driven force and interaction effects through multichannel interference. The experimental indication of these nonadiabatic dynamics is also discussed.

cond-mat.quant-gas↗