@article {3080, title = {Combining machine learning with physics: A framework for tracking and sorting multiple dark solitons}, journal = {Phys. Rev. Research}, volume = {4}, year = {2022}, month = {06/01/2022}, pages = {023163 }, abstract = {

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 among excitations in Bose-Einstein condensates (BECs). In this paper, we describe a framework combining machine learning (ML) models with physics-based traditional analyses to identify and track multiple solitonic excitations in images of BECs. We use an ML-based object detector to locate the solitonic excitations and develop a physics-informed classifier to sort solitonic excitations into physically motivated subcategories. Lastly, we introduce a quality metric quantifying the likelihood that a specific feature is a longitudinal soliton. Our trained implementation of this framework, SolDet, is publicly available as an open-source python package. SolDet is broadly applicable to feature identification in cold-atom images when trained on a suitable user-provided dataset.

}, doi = {https://doi.org/10.1103/PhysRevResearch.4.023163}, url = {https://arxiv.org/abs/2111.04881}, author = {Shangjie Guo and Sophia M. Koh and Amilson R. Fritsch and I. B. Spielman and Justyna P. Zwolak} } @article {3079, title = {Dark Solitons in Bose-Einstein Condensates: A Dataset for Many-body Physics Research}, year = {2022}, month = {05/17/2022}, abstract = {

We establish a dataset of over 1.6\×104 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 is automatically labeled using SolDet -- an implementation of a physics-informed ML data analysis framework -- consisting of a convolutional-neural-network-based classifier and object detector as well as a statistically motivated physics-informed classifier and a quality metric. This technical note constitutes the definitive reference of the dataset, providing an opportunity for the data science community to develop more sophisticated analysis tools, to further understand nonlinear many-body physics, and even advance cold atom experiments.

}, url = {https://arxiv.org/abs/2205.09114}, author = {Amilson R. Fritsch and Shangjie Guo and Sophia M. Koh and I. B. Spielman and Justyna P. Zwolak} } @article {2730, title = {Machine-learning enhanced dark soliton detection in Bose-Einstein condensates}, journal = {Mach. Learn.: Sci. Technol. }, volume = {2}, year = {2021}, month = {6/17/2021}, pages = {035020}, abstract = {

Most data in cold-atom experiments comes from images, the analysis of which is limited by our preconceptions of the patterns that could be present in the data. We focus on the well-defined case of detecting dark solitons -- appearing as local density depletions in a BEC -- using a methodology that is extensible to the general task of pattern recognition in images of cold atoms. Studying soliton dynamics over a wide range of parameters requires the analysis of large datasets, making the existing human-inspection-based methodology a significant bottleneck. Here we describe an automated classification and positioning system for identifying localized excitations in atomic Bose-Einstein condensates (BECs) utilizing deep convolutional neural networks to eliminate the need for human image examination. Furthermore, we openly publish our labeled dataset of dark solitons, the first of its kind, for further machine learning research.

}, doi = {https://doi.org/10.1088/2632-2153/abed1e}, url = {https://arxiv.org/abs/2101.05404}, author = {Shangjie Guo and Amilson R. Fritsch and Craig Greenberg and I. B. Spielman and Justyna P. Zwolak} } @article {2648, title = {Feedback Induced Magnetic Phases in Binary Bose-Einstein Condensates}, year = {2020}, month = {7/14/2020}, abstract = {

Weak measurement in tandem with real-time feedback control is a new route toward engineering novel non-equilibrium quantum matter. Here we develop a theoretical toolbox for quantum feedback control of multicomponent Bose-Einstein condensates (BECs) using backaction-limited weak measurements in conjunction with spatially resolved feedback. Feedback in the form of a single-particle potential can introduce effective interactions that enter into the stochastic equation governing system dynamics. The effective interactions are tunable and can be made analogous to Feshbach resonances -- spin-independent and spin-dependent -- but without changing atomic scattering parameters. Feedback cooling prevents runaway heating due to measurement backaction and we present an analytical model to explain its effectiveness. We showcase our toolbox by studying a two-component BEC using a stochastic mean-field theory, where feedback induces a phase transition between easy-axis ferromagnet and spin-disordered paramagnet phases. We present the steady-state phase diagram as a function of intrinsic and effective spin-dependent interaction strengths. Our result demonstrates that closed-loop quantum control of Bose-Einstein condensates is a powerful new tool for quantum engineering in cold-atom systems.

}, url = {https://arxiv.org/abs/2007.07266}, author = {Hilary M. Hurst and Shangjie Guo and I. B. Spielman} } @article {2516, title = {Beyond Spontaneous Emission: Giant Atom Bounded in Continuum}, year = {2019}, month = {12/20/2019}, abstract = {

The quantum coupling of individual superconducting qubits to microwave photons leads to remarkable experimental opportunities. Here we consider the phononic case where the qubit is coupled to an electromagnetic surface acoustic wave antenna that enables supersonic propagation of the qubit oscillations. This can be considered as a giant atom that is many phonon wavelengths long. We study an exactly solvable toy model that captures these effects, and find that this non-Markovian giant atom has a suppressed relaxation, as well as an effective vacuum coupling between a qubit excitation and a localized wave packet of sound, even in the absence of a cavity for the sound waves. Finally, we consider practical implementations of these ideas in current surface acoustic wave devices.\ 

}, url = {https://arxiv.org/abs/1912.09980}, author = {Shangjie Guo and Yidan Wang and Thomas Purdy and J. M. Taylor} }