研究・研究者
研究会・セミナー
| 演 題 | 「Coherent control of the photoassociation of ultracold molecules」 |
|---|---|
| 日 時 | 2013年05月07日(火) 15:00 |
| 講演者 | Prof. Dr. Christiane Koch (University of Kassel) |
| 場 所 | 実験棟3階 301セミナー室 |
| 概 要 | In photoassociation at ultralow temperature, two colliding atoms are excited by laser light to weakly bound levels of an electronically excited state. A pair of short laser pulses may be employed in a pump-dump sequence to produce ultracold molecules in their electronic ground state. For one-photon transitions, picosecond pulses turn out to be best suited based on the consideration of timescales, bandwidths and Franck-Condon factors. The broad bandwidth of femtosecond lasers can be fully utilized to drive the narrow band photoassociation transition when employing optical interferences in multi-photon excitation. The structure of ultracold molecules is precisely known, and their dynamics is very sensitive to small changes in this structure. This allows one to take the coherent control concept of shaping the potential energy surfaces which govern the dynamics literally: Resonances can be induced or possibly suppressed by external fields leading to a qualitative change of the dynamics. This talk will introduce intuitive photoassociation schemes and discuss how various concepts of coherent control may be employed to improve the overall molecule yield as well as the final state control. |
| お問合せ先 | 武井貞幸・大森賢治 |
