Preliminary Exam |
Events During the Week of August 24th through August 31st, 2025
Monday, August 25th, 2025
- Applications of the 6s-5d quadrupole transition in neutral Cesium atoms
- Time: 9:00 am - 11:00 pm
- Place: 5310 Chamberlin
- Speaker: Hong Ming Lim , Physics PhD Graduate Student
- Abstract: The 6s–5d electronic transition in neutral cesium atoms is a forbidden transition, and therefore has a narrow linewidth. This transition can be used in laser cooling to achieve a low Doppler temperature. One limitation of the conventional imaging method for atomic states through allowed transitions is the background light arising from the excitation laser scattered by surfaces and objects near the trapped atoms. Excited cesium atoms in the 5d state decay primarily through dipole-allowed transitions to intermediate states and emit photons at wavelengths longer than that of the excitation laser. This property can be used to perform background-free, state-selective fluorescence imaging, enabling higher fidelity and shorter imaging times. In this talk, I will present an overview of the experiments we are conducting to push the limits of high-fidelity, fast atomic state readout using this transition.
- Host: Mark Saffman
Tuesday, August 26th, 2025
- No events scheduled
Wednesday, August 27th, 2025
- Quantum statistics of single mode light interacting with an atomic ensemble
- Time: 2:00 pm - 4:00 pm
- Place: 5310 Chamberlin
- Speaker: Anirudh Yadav, Physics PhD Graduate Student
- Abstract: We study the quantum statistics of single-mode radiation emitted by an atomic ensemble when the ensemble is initially prepared in a superradiant Dicke state. We show that while the radiation is well approximated by the Glauber coherent state at early times in the evolution, the emission can be truly quantum at later times. In particular, one can observe a large amount of photon-number squeezing in the emission under certain conditions; even a Fock state can be produced. We discuss the quantum statistics of the emission for various parameters, including different initial conditions for the atomic ensemble. To obtain these results, we have developed a formalism where we are able to calculate the quantum statistics of the emission over long time-scales even when the number of atoms in the ensemble is quite large.
- Host: Deniz Yavuz
Thursday, August 28th, 2025
- No events scheduled
Friday, August 29th, 2025
- Progress toward efficient quantum networking with neutral atoms
- Time: 2:00 pm - 4:00 pm
- Place: B343 Sterling
- Speaker: Eunji Oh, Physics PhD Graduate Student
- Abstract: Development of quantum networks that interconnect multiple quantum processors is a central goal in quantum information science. Such networks enable remote entanglement, distributed quantum computing and quantum sensing. To make this possible, it is crucial to realize a robust and scalable platform which can serve as a building block of a quantum network. In this talk, I will present our recent progress toward building a quantum networking node capable of storing, processing, and distributing quantum information. Our system uses a compact, fiber-integrated, plug-and-play architecture based on a parabolic mirror, with two such nodes currently in operation. I will highlight our efforts to generate atom-photon entanglement between a stationary qubit (Rb-87 atom) and a flying qubit (photon), as well as discuss our future plans for achieving atom-atom entanglement - a key primitive for long-distance quantum networking. In addition to our networking efforts, I will also present our development of a fast and scalable method in controlling the quantum state of qubits in large 2D arrays. While spatial light modulators (SLMs) offer flexible control, their slow response times limit their use in fast quantum gate operations. We address this by combining an SLM with a high-speed deflector to create a hybrid beam scanner. This approach enables rapid, site-selective quantum state manipulation with addressing rates orders of magnitude faster than SLMs alone.
- Host: Mark Saffman