Cold Rydberg Gases - from frequency conversion to single-particle imaging

报告题目:Cold Rydberg Gases - from frequency conversion to single-particle imaging

报告人:李文辉 教授(新加坡国立大学量子技术中心)




Recently, the experimental platform based on Rydberg atoms has made rapid progresses along diverse directions, including quantum simulation and computation, quantum nonlinear effects, as well as microwave electric field sensing. In this talk, I will first give a very brief overview of current research with Rydberg atoms. I will then focus on discussing two recent experiments that we carried out in cold Rydberg gases. In a pioneering experiment, we had demonstrated coherent conversion from microwave to optical field via six-wave mixing in Rydberg atoms, utilizing the strong coupling of microwaves to Rydberg transitions. This scheme has achieved the highest conversion efficiency (internal) and become one of the leading methods to make microwave-optical conversion for quantum networking and quantum measurements. In another experimental effort, we pursue non-destructive imaging of individual particles via Rydberg-blockade-induced absorption. By utilizing multiphoton electromagnetically induced transparency involving Rydberg states (Rydberg EIT), we are able to imaging single ions and single Rydberg excitations in an atomic ensemble within single-shot of ~1 µs exposure time. This imaging technique will be well-suited for the investigation of single-particle quantum dynamics, be that in cold hybrid ion-atom mixtures or of Rydberg “superatoms” for quantum technologies.


After graduating from Fudan Univesity, Wenhui Li went to the University of Virginia to pursue her PhD study in the group of Tom Gallagher. Her PhD research was in the field of cold Rydberg gases, especially on studying dipole-dipole interactions between Rydberg atoms using millimeter waves spectroscopy. Upon the completion of PhD degree in 2005, she joined Randy Hulet’s group at Rice University as a postdoctoral researcher, and worked on strongly interacting degenerate Fermi gases. In 2009, Wenhui became a principal investigator at the Center for Quantum Technologies, with a joint faculty appointment at the National University of Singapore. Her experimental group at CQT researches on Rydberg atoms in several areas, including nonlinear processes for microwave-optical conversion and for THz generation, nondestructive optical imaging of ions and Rydberg atoms, and coherent dipole-dipole energy transfer of Rydberg excitations.