Seminar by Dr Du, 'Measurement and control of single atoms in a cavity QED system'

Speaker:
Mr Jinjin Du
State Key Laoratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, China

Seminar Title:
Measurement and control of single atoms in a cavity QED system

Abstract:
We have demonstrated the strong coupling between single 133Cs atoms and the higher-order Hermite-Gaussian transverse mode TEMm0 (m=0,1,2,3) in a high-finesse optical micro-cavity. Compared to the usual low-order symmetric transverse modes, multiple lobes and the asymmetric spatial pattern of the titled modes provide more information about the motion of single atoms in the cavity. The motional information can be extracted from the measured transmission spectra, which includes the velocities and the positions of the atoms in vertical and off-axis directions. By measuring the transmission spectra of large number of atoms, the absorption spectra of the cavity induced by single atoms are obtained. Monte Carlo simulations agree with the experimental results, and the initial temperature of the cold atoms in the MOT is determined which sheds new light on determining temperature of cold atoms by counting atoms individually in a confined space. Single atoms are also cooled and trapped inside the micro-cavity by using an intracavity far-off resonance trap (FORT) and can be continuously observed via transmission of the probe beam.

References:
[1] Pengfei Zhang,Yanqiang Guo, Zhuoheng Li, Yuchi Zhang, Yanfeng Zhang, Jinjin Du , Gang Li, Junmin Wang and Tiancai Zhang. Phys. Rev. A, 83, 031804(R)(2011)
[2] Jinjin Du , Wenfang Li, Ruijuan Wen, Gang Li, P.F. Zhang and Tiancai Zhang, Appl.Phys. Lett. 103, 083117 (2013)
[3] Wenfang Li, Jinjin Du, Ruijuan Wen, Pengfei Yang, Gang Li, Junjun Liang and Tiancai Zhang , Appl. Phys. Lett. 104, 113102 (2014).
[4] Wenfang Li, Jinjin Du, Ruijuan Wen, Gang Li, and Tiancai Zhang, J. Appl. Phys. 115, 123106 (2014)