The precise control of direct current (dc) magnetic fields is crucial in a wide range of experimental platforms, from ultracold quantum gases and nuclear magnetic resonance to precision measurements. In each of these cases, the Zeeman effect causes quantum states …

A 20 A bipolar current source with 140 μA noise over 100 kHz bandwidth Read more »

In cold atom experiments, each image of light refracted and absorbed by an atomic ensemble carries a remarkable amount of information. Numerous imaging techniques including absorption, fluorescence, and phase-contrast are commonly used. Other techniques such as off-resonance defocused imaging (ORDI, …

Multiple-camera defocus imaging of ultracold atomic gases Read more »

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 »