We quantum simulated the 2D Harper-Hofstadter (HH) lattice model in a highly elongated tube geometry—three sites in circumference—using an atomic Bose-Einstein condensate. In addition to the usual transverse (out-of-plane) magnetic flux, piercing the surface of the tube, we threaded a …

Coherence and decoherence in the Harper-Hofstadter model Read more »

Spielman group alumna Dr. Dina Genkina has composed a high level write-up of Dr. Ana Valdés-Curiel’s Rashba paper! https://jqi.umd.edu/news/researchers-comb-atoms-into-novel-swirl Topological features without a lattice in Rashba spin-orbit coupled atoms; A. Valdés-Curiel, D. Trypogeorgos, Q.-Y. Liang, R. P. Anderson, and I. …

JQI writeup of: Topological features without a lattice in Rashba spin-orbit coupled atoms Read more »

Topological order can be found in a wide range of physical systems, from crystalline solids, photonic meta-materials and even atmospheric waves to optomechanic, acoustic and atomic systems. Topological systems are a robust foundation for creating quantized channels for transporting electrical …

Topological features without a lattice in Rashba spin-orbit coupled atoms Read more »

We propose and describe our realization of a deeply subwavelength optical lattice for ultracold neutral atoms using N resonantly Raman-coupled internal degrees of freedom. Although counterpropagating lasers with wavelength λ provided two-photon Raman coupling, the resultant lattice period was λ/2N, an N-fold reduction as compared to …

Realization of a deeply subwavelength adiabatic optical lattice Read more »

We describe a Fourier transform spectroscopy technique for directly measuring band structures, and apply it to a spin-1 spin–orbit coupled Bose–Einstein condensate. In our technique, we suddenly change the Hamiltonian of the system by adding a spin–orbit coupling interaction and …

Fourier transform spectroscopy of a spin–orbit coupled Bose gas Read more »

We observed a new mechanism for vortex nucleation in Bose–Einstein condensates (BECs) subject to synthetic magnetic fields. We made use of a strong synthetic magnetic field initially localized between a pair of merging BECs to rapidly create vortices in the …

Vortex nucleation in a Bose–Einstein condensate: from the inside out Read more »