Atomic Physics Seminars |
Events During the Week of February 18th through February 25th, 2024
Monday, February 19th, 2024
- Using precision measurements to study the interplay of quantum mechanics and gravity and explore the universe
- Time: 12:00 pm - 1:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Tejas Deshpande, Northwestern University
- Abstract: Gravity is the least understood of the four fundamental forces at a microscopic level. Moreover, quantum phenomena are typically challenging to observe in macroscopic systems. An overlap between gravitational and quantum phenomena is expected to occur at very high energies like those inside a black hole or close to the big bang. Precision measurements offer an alternate low-energy route to studying such phenomena in tabletop experiments. Furthermore, precision measurement tools can be used for cosmic exploration through detection of gravitational waves (GWs) and direct detection of dark matter (DM). In this talk, I will discuss three current experiments aiming to investigate such phenomena of great importance to fundamental physics research. The first experiment involves performing light-pulse atom interferometry (LPAI) over a 100 m vertical baseline and is part of an international collaboration called Matter-wave Atomic Gradiometer Interferometric Sensor (MAGIS). I will discuss the work done by our group at Northwestern University (NU) on the design, construction, and testing of the laser system for MAGIS. I will present empirical and simulation results demonstrating the potential of MAGIS to detect GWs and ultralight DM at mid-band frequencies (0.03-3 Hz) with unprecedented sensitivity. Moreover, I will discuss how MAGIS can study macroscopic quantum phenomena by creating quantum superpositions of massive systems separated by tens of meters. The second experiment aims to use LPAI to measure Newton's gravitational constant, to a precision of less than 10 parts per million, using a 2 m vertical baseline at NU. I will present some recent results from the first stage of the NU apparatus utilizing resonant LPAI, with a record 504 loops, and discuss its implications for MAGIS. The third experiment involves detecting ultralight DM using cryogenic Fabry-Perot cavities at NU. I will conclude with some ideas for near-future experiments which aim to study the interplay of quantum mechanics and gravity using a combination of technologies associated with LPAI, laser interferometry, and kilogram-scale levitation.
- Host: Thad Walker
Tuesday, February 20th, 2024
- No events scheduled
Wednesday, February 21st, 2024
- Cavity-enabled measurements and interactions in neutral atoms
- Time: 12:00 pm - 1:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Zhenjie Yan, UC Berkeley
- Abstract: Control over interactions and measurements in quantum systems is crucial for applications such as quantum simulation and computation. In this talk, I will highlight our recent progress in realizing nondestructive readout and long-range interactions in atomic tweezer arrays using a strongly coupled optical cavity. Through selectively coupling a single atom with the cavity mode, we achieve a rapid mid-circuit measurement without perturbing the quantum coherence of the other atoms. Conversely, the collective emission from multiple atoms into the cavity can be coherently enhanced or suppressed. By controlling the atom-cavity interaction at the single-atom level, we observe both super- and subradiant cavity emissions from the constructed atomic ensembles. I will then discuss how we engineer long-range mechanical interactions via photon exchange and present our recent observation of a self-organization phase transition in a mesoscopic system. Finally, I will discuss how the cavity can be used to monitor and manipulate strongly interacting quantum gases, opening new avenues for experimental research in quantum many-body physics.
- Host: Thad Walker
Thursday, February 22nd, 2024
- No events scheduled
Friday, February 23rd, 2024
- No events scheduled