We study the interplay between large-spin, spin-orbit coupling, and superfluidity for bosons in a two-dimensional optical lattice, focusing on the spin-1 spin-orbit-coupled system recently realized at the Joint Quantum Institute [Campbell et al., arXiv:1501.05984]. We find a rich quantum phase …

Interaction-driven exotic quantum phases in spin-orbit-coupled spin-1 bosons Read more »

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 »

We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by …

Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems 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 »

Nathan Goldman et al‘s result describing techniques for measuring topology in a laser-coupled honeycomb lattice has been featured as a “Highlight of 2013” by The New Journal of Physics! This rocks! Highlights page: http://iopscience.iop.org/1367-2630/page/highlights-of-2013 Article: http://iopscience.iop.org/1367-2630/15/1/013025/article

We explore the time evolution of two-component Bose-Einstein condensates (BECs), quasi one dimensional with respect to their spinor dynamics, following a quench from one component BECs with a U(1) order parameter into two-component condensates with a U(1)xZ2 order parameter. In …

Quenched binary Bose-Einstein condensates: Spin-domain formation and coarsening Read more »

Resonant absorption imaging is a common technique for detecting the two-dimensional column density of ultracold atom systems. In many cases, the system’s thickness along the imaging direction greatly exceeds the imaging system’s depth of field, making the identification of the …

Optimally focused cold atom systems obtained using density-density correlations Read more »