HQAN Exchange Visit to Professor Mark Saffman's Lab at UW-Madison

Mingjiamei Zhang, a PhD student at UChicago student studying Experimental Atomic Physics in Prof. Cheng Chin's lab, visited University of Wisconsin–Madison and toured Prof. Mark Saffman’s lab in early August of 2022. This visit was supported by the HQAN Student Exchange Program, which is open to all graduates and post-docs advised by HQAN-affiliated faculty.

Zhang described her visit as “full of intriguing discussions, especially on the technical aspect of experiments”. Trent Graham, a postdoctoral scientist in the Saffman Lab, thoroughly introduced Zhang to the setup of a cesium array experiment, demonstrating the computer control and monitor system, vacuum chamber design, optical trap generation, cooling and imaging schemes, and RF and microwave control hardware. Zhang was impressed by Graham’s wide technical knowledge, as well as the complexity of the experiments.

Saffman’s group developed technology to trap a large atom array, which reshapes laser beams to top-hat intensity profile and expands the beam to lines which cross each other to form the blue-detuned traps. Zhang’s project also involves building blue-detuned arrays of optical tweezers to confine atoms, and she noted “[the Saffman lab’s] experience provides very insightful ideas on designing the trap geometry, and making me aware of the potential technical challenges”.

She also learned about the application of the optical cavity. The Saffman group used a high-finesse optical cavity very extensively in their experiment. She found their techniques very inspiring, and following the visit, thought of a few possible applications in her own lab.

In addition to the cesium array lab, Graham introduced Zhang to other experiments of the Saffman group: a rubidium-cesium dual species experiment, a hybrid quantum system that involves coupling between phonons and atoms, and a quantum network experiment. Zhang had the opportunity to speak with a few graduate students who work on the projects, and see designs and proposals for in-progress experiments.

Zhang strongly recommends that students and postdocs affiliated with HQAN participate in the HQAN exchange programs. She found her visit to be incredibly valuable and is grateful to HQAN for the opportunity to tour the Saffman lab and speak with individuals with information relevant to her own research. “The Saffman lab is great and I’ve learned a lot!” she stated.

Zhang’s visit was financially supported by the HQAN Student Exchange Program, which is open to all HQAN-affiliated graduate students and post-docs. Those interested in visiting an HQAN-affiliated lab should contact their HQAN faculty advisors and refer questions to HQAN's outreach coordinator Mallory Conlon.