Synopsis: Rotating condensates show new vortex behavior

Acousto-optical techniques can be used to access a new regime of vortex nucleation in condensates in optical lattices with deep potential wells.
Synopsis figure
Figure credit: Alan Stonebraker

Ultracold atoms trapped in optical lattices provide a controllable way to study phenomena found in condensed matter, such as Mott-insulator transitions and Anderson localization. By rotating quantum gases one can simulate what happens when a magnetic field is applied to such condensed matter analogs. Now, writing in Physical Review Letters, Ross Williams, Sarah Al-Assam, and Christopher Foot of Oxford University, UK, combine these two approaches to investigate the effects on an ultracold quantum gas placed in rotating optical lattice.

A rubidium-87 condensate was created with conventional cooling and trapping methods, while interference of four intersecting laser beams formed the 2D optical lattice. Acousto-optical deflectors were used to rotate these laser beams, and hence the lattice, about a central axis. This rotation led to the formation of vortices, and the authors were able to track the number of vortices as a function of rotation frequency and depth of the lattice wells. Williams et al. found a new regime for vortex nucleation: when the lattice wells are deep, the novel behavior indicated that the vortices were formed locally at a lattice plaquette, created by rotation-induced phase differences between condensates localized at different lattice sites. – David Voss


Announcements

More Announcements »

Subject Areas

Atomic and Molecular Physics

Previous Synopsis

Next Synopsis

Related Articles

Synopsis: Losing Light in a BEC
Atomic and Molecular Physics

Synopsis: Losing Light in a BEC

The index of refraction in a gas of bosons is enhanced relative to its value in a classical gas, a predicted quantum effect that has now been observed in ultracold sodium atoms. Read More »

Focus: Atoms As Thermometers
Atomic and Molecular Physics

Focus: Atoms As Thermometers

A small number of atoms in repeated trials can accurately measure the temperature of an ultracold gas cloud—a step toward measuring temperature on the micrometer scale. Read More »

Synopsis: Bad Cavities for Precise Lasers
Optics

Synopsis: Bad Cavities for Precise Lasers

The frequency of a laser based on trapped ultracold atoms can be made insensitive to fluctuations in the laser cavity’s length. Read More »

More Articles