We directly measured the normalized s-wave scattering cross-section of ultracold 40K atoms across a magnetic-field Feshbach resonance by colliding pairs of degenerate Fermi gases (DFGs) and imaging the scattered atoms. We extracted the scattered fraction for a range of bias …

Feshbach enhanced s-wave scattering of fermions: direct observation with optimized absorption imaging Read more »

Bringing ultracold atomic gases into the quantum Hall regime is challenging. We engineered an effective magnetic field in a two-dimensional lattice with an elongated-strip geometry, consisting of the sites of an optical lattice in the long direction and of three …

Published in Science: Visualizing edge states with an atomic Bose gas in the quantum Hall regime Read more »

The order parameter of a quantum-coherent many-body system can include a phase degree of freedom, which, in the presence of an electromagnetic field, depends on the choice of gauge. Because of the relationship between the phase gradient and the velocity, …

Gauge matters: observing the vortex-nucleation transition in a Bose condensate Read more »

Spin-orbit coupling is an essential ingredient in topological materials, conventional and quantum-gas-based alike. Engineered spin-orbit coupling in ultracold-atom systems—unique in their experimental control and measurement opportunities—provides a major opportunity to investigate and understand topological phenomena. Here we experimentally demonstrate and …

Tunable Spin-Orbit Coupling via Strong Driving in Ultracold-Atom Systems Read more »

Ultracold gases of interacting spin-orbit-coupled fermions are predicted to display exotic phenomena such as topological superfluidity and its associated Majorana fermions. Here, we experimentally demonstrate a route to strongly interacting single-component atomic Fermi gases by combining an s-wave Feshbach resonance (giving …

Raman-Induced Interactions in a Single-Component Fermi Gas Near an s-Wave Feshbach Resonance Read more »