Photoassociative Production And Spectroscopic Measurement Of Ultracold RbCs Polar Molecules

Ultracold atoms move slowly and can be seen as static, the corresponding temperature is below 1mK. Atomic systems in such low temperatures show a number of special qualities and comply with some new laws of physics. In current, ultracold atoms have been widely applied to many fields. For example, the research and application of optical frequency atomic clocks, the research of quantum many-body systems using quantum optics, et al.Researchers produce ultracold polar molecules on the basis of ultracold atoms. And now ultracold polar molecules have been a topic, which are widely used in high-resolution spectroscopy, ultracold collisions and ultracold chemistry. Because of their permanent dipole moments, and long-range anisotropic dipole-dipole interactions, ultracold polar molecules can be manipulated with external electric fields. The ultracold polar molecules can be used in the fields of quantum information processing and quantum computing.In this thesis, the high-density ultracold rubidium and cesium atomic sample are cooled and trapped at the same time in the magneto-optical trap. Ultracold excited-state RbCs molecules are produced via photoassociation. As the excited-state molecular life is short, these molecules will soon decay to ground state through spontaneous emission. The ground state RbCs molecules are detected by resonance-enhanced two-photon ionization (RETPI), the photoassociative spectroscopy is studied at the same time.The main works are as follows:1. The high-density ultracold rubidium and cesium atomic sample are cooled and trapped at the same time in the magneto-optical trap. The number and density of the rubidium atomic sample are 2×108 and 3×1011 cm-3, the number and density of the cesium atomic sample are 3×108 and 6×1011 cm-3, respectively. The temperatures of rubidium and cesium atoms are 100μK and 70μK, respectively.2. The a3Σ+ state molecules are detected by resonance-enhanced two-photon ionization. The new rovibrational spectroscopy of RbCs molecules in the v=189, (2)0- state below the 5S1/2+6P1/2 dissociation limit is observed for the first time in the experiment. And the corresponding rotational constants are measured, which is about 0.00443cm-1.3. We made the line shape analysis of photoassociative spectroscopy for RbCs, which is in the (2)3Π state below the Rb(5P1/2)+Cs(6S1/2) dissociation limit. Contents are as follows; the relationship between RbCs molecular photoassociation spectroscopy intensity for J=0,1, and 2 rotational states and ionization laser energy, the relationship between RbCs molecular photoassociation spectroscopy intensity for J=0,1, and 2 rotational states and photoassociation laser energy, the relationship between full width at half maximum (FWMH) of photoassociation line-width for J=0,1, and 2 rotational states and photoassociation laser energy.