A majority of ultracold atom experiments utilize resonant absorption imaging techniques to obtain the atomic density. To make well-controlled quantitative measurements, the optical intensity of the probe beam must be precisely calibrated in units of the atomic saturation intensity Isat. In …
Direct calibration of laser intensity via Ramsey interferometry for cold atom imaging Read more »
A fundamental tenet of quantum mechanics is that measurements change a system’s wavefunction to that most consistent with the measurement outcome, even if no observer is present. Weak measurements produce only limited information about the system, and as a result …
Quantum back-action limits in dispersively measured Bose-Einstein condensates Read more »
We describe a two-dimensional optical lattice for ultracold atoms with spatial features below the diffraction limit created by a bichromatic optical standing wave. At every point in space these fields couple the internal atomic states in a three-level Lambda coupling …
Interference induced anisotropy in a two-dimensional dark state optical lattice Read more »
Recent experiments demonstrated deeply subwavelength lattices using atoms with N internal states Raman coupled with lasers of wavelength λ. The resulting unit cell was λ/2N in extent, an N-fold reduction compared to the usual λ/2 periodicity of an optical lattice. For resonant Raman coupling, this lattice consists of N independent …
Topological charge pumping with subwavelength Raman lattices Read more »
Fab science communicator and group alum Dina Genkina has done a great writeup of our recent results! Dynamically Induced Symmetry Breaking and Out-of-Equilibrium Topology in a 1D Quantum System; G. H. Reid, M. Lu, A. R. Fritsch, A. M. Piñeiro, …
JQI writeup: Twisting Up Atoms Through Space and Time Read more »
We establish a dataset of over 1.6 x 10^4 experimental images of Bose–Einstein condensates containing solitonic excitations to enable machine learning (ML) for many-body physics research. About 33% of this dataset has manually assigned and carefully curated labels. The remainder …
Dark solitons in Bose–Einstein condensates: a dataset for many-body physics research Read more »
Here we revisit the topic of stationary and propagating solitonic excitations in self-repulsive three-dimensional (3D) Bose–Einstein condensates by quantitatively comparing theoretical analysis and associated numerical computations with our experimental results. Motivated by numerous experimental efforts, including our own herein, we …
Dynamical instability of 3d stationary and traveling planar dark solitons Read more »
Nontrivial topology in lattices is characterized by invariants—such as the Zak phase for one-dimensional (1D) lattices—derived from wave functions covering the Brillouin zone. We realize the 1D bipartite Rice-Mele (RM) lattice using ultracold 87Rb and focus on lattice configurations possessing …
We experimentally realized a time-periodically modulated 1D lattice for ultracold atoms featuring a pair of linear bands, each with a Floquet winding number. These bands are spin-momentum locked and almost perfectly linear everywhere in the Brillouin zone: a near-ideal realization …
In ultracold-atom experiments, data often comes in the form of images which suffer information loss inherent in the techniques used to prepare and measure the system. This is particularly problematic when the processes of interest are complicated, such as interactions …