Spin–orbit coupling links a particle’s velocity to its quantum-mechanical spin, and is essential in numerous condensed matter phenomena, including topological insulators and Majorana fermions. In solid-state materials, spin–orbit coupling originates from the movement of electrons in a crystal’s intrinsic electric …

Review: Spin-orbit coupling in atomic gases Read more »

We have observed well-defined phase slips between quantized persistent current states around a toroidal atomic (23Na) Bose-Einstein condensate. These phase slips are induced by a weak link (a localized region of reduced superfluid density) rotated slowly around the ring. This …

Driving Phase Slips in a Superfluid Atom Circuit with a Rotating Weak Link Read more »

We present a method for accurate determination of atomic transition matrix elements at the 10-3 level. Measurements of the ac Stark (light) shift around “magic-zero” wavelengths, where the light shift vanishes, provide precise constraints on the matrix elements. We make …

Precision Measurement of Transition Matrix Elements via Light Shift Cancellation Read more »

We have created a long-lived (≈40  s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect …

Superflow in a Toroidal Bose-Einstein Condensate: An Atom Circuit with a Tunable Weak Link Read more »