Sculpting the Vortex State of a Spinor BEC

Abstract

We use Raman-detuned laser pulses to achieve spatially varying control of the amplitude and phase of the spinor order parameter of a Bose-Einstein condensate. We present experimental results confirming precise radial and azimuthal control of amplitude and phase during the creation of vortex-antivortex superposition states.

Angular spin-orbit coupling in cold atoms

“…Via a two-photon Raman process [20], the lasers couple two hyperfine states of the atom that we label as ↑,↓. Under the rotating wave approximation, the following Hamiltonian can be derived [18,20,21]:…”

“…Manipulating cold atoms with LG beams has been studied both experimentally and theoretically, in the context of quantum information storage [15], slow light propagation [16], synthetic gauge fields [17], etc. The experiments that directly motivated our investigations [18,19] used LG beams to diabatically write phase windings and spin textures into a BEC, producing coreless vortices and Skyrmions in the process. Our predictions are related to these results, though we focus on the adiabatic regime and consider the ground states of these systems.…”

Inducing vortices in a Bose-Einstein condensate using holographically produced light beams

“…In biophysics and micromechanics this torque has been proposed to be utilizable in driving molecular motors and micromachines, which can at the same time be trapped at the location of the singularity, where the beam intensity has to vanish [1,[8][9][10]. Also, in the field of ultracold atoms, direct transfer of OAM from light to atoms in an ultracold gas cloud offers interesting possibilities [11][12][13][14].…”

Optical manipulation of matter-wave vortices: An analog of circular dichroism

“…One can detect the presence and sign of the undisturbed vortex by doing measurements on the separated part. In recent experiments of [11,14,15], two-photon transitions are used to transfer the OAM to the atomic BEC employing an LG and a Gaussian beam.…”

“…Numerous theoretical and experimental studies related to creation of matter-wave vortex states, persistent current in BEC and coherent control of the OAM of atoms using interaction of ultra-cold atoms with optical vortex [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] have been reported over past two decades. Quantized vortex states play an essential role in macroscopic quantum phenomena like superfluidity and superconductivity.…”