Ultracold polar RbCs molecules are produced via photoassociation in a laser-cooled mixture of ^85Rb and ^133Cs atoms. The a3∑+ state molecules which decay from electronically excited (2)0- state RbCs molecules are...Ultracold polar RbCs molecules are produced via photoassociation in a laser-cooled mixture of ^85Rb and ^133Cs atoms. The a3∑+ state molecules which decay from electronically excited (2)0- state RbCs molecules are detected by resonance- enhanced two-photon ionization. The new rovibrational levels (v = 189, 190) in the (2)0- state are also observed, which exist in theory and have not been observed in experiments yet. The corresponding rotational constants are measured by photoassociation spectroscopy, which are consistent with theoretical calculations using a nonrigid rotor model.展开更多
We systematically investigate the polarization gradient cooling (PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequenc...We systematically investigate the polarization gradient cooling (PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequency is stepped to the setting value while its intensity is ramped, is found to be the best for the PGC, compared with other modes studied. We verify that the heating effect of the cold atoms, which appears when the cooling laser intensity is lower than the saturation intensity, arises from insufficient polarization gradient cooling. Finally, an exponential decay function with a statistical explanation is introduced to explain the dependence of the cold atom temperature on the PGC interaction time.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2012CB921603)the International Science & Technology Cooperation Program of China (Grant No. 2011DFA12490)+1 种基金the National Natural Science Foundation of China (Grant Nos. 61275209, 10934004, and 11004125)the National Natural Science Foundation for Excellent Research Team, China (Grant No. 61121064)
文摘Ultracold polar RbCs molecules are produced via photoassociation in a laser-cooled mixture of ^85Rb and ^133Cs atoms. The a3∑+ state molecules which decay from electronically excited (2)0- state RbCs molecules are detected by resonance- enhanced two-photon ionization. The new rovibrational levels (v = 189, 190) in the (2)0- state are also observed, which exist in theory and have not been observed in experiments yet. The corresponding rotational constants are measured by photoassociation spectroscopy, which are consistent with theoretical calculations using a nonrigid rotor model.
基金supported by the National Basic Research Program of China(Grant Nos.2012CB921603 and 2010CB923103)the International Science &Technology Cooperation Program of China(Grant No.2011DFA12490)+2 种基金the National Natural Science Foundation of China(Grant Nos.11304189,61378015,and 61275209)the Project for Excellent Research Team of the National Natural Science Foundation of China(Grant No.61121064)the Program for Changjiang Scholars,China,and the Innovative Research Team in University,China(Grant No.IRT13076)
文摘We systematically investigate the polarization gradient cooling (PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequency is stepped to the setting value while its intensity is ramped, is found to be the best for the PGC, compared with other modes studied. We verify that the heating effect of the cold atoms, which appears when the cooling laser intensity is lower than the saturation intensity, arises from insufficient polarization gradient cooling. Finally, an exponential decay function with a statistical explanation is introduced to explain the dependence of the cold atom temperature on the PGC interaction time.