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Ultracold polar RbCs molecules are produced via photoassociation in a laser-cooled mixture of 85Rb and 133Cs atoms. The a3Σ+ 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. [ABSTRACT FROM AUTHOR]

In this paper, ultracold atoms and molecules in a dark magneto-optical trap (MOT) are studied via depumping the cesium cold atoms into the dark hyperfine ground state. The collision rate is reduced to 0.45 s-1 and the density of the atoms is increased to 5:6 ✕ 1011 cm-3 when the fractional population of the atoms in the bright hyperfine ground state is as low as 0.15. The vibrational spectra of the ultracold cesium molecules are also studied in a standard MOT and in a dark MOT separately. The experimental results are analyzed by using the perturbative quantum approach. [ABSTRACT FROM AUTHOR]

The quantum noise of squeezed probe light passing through an atomic system with different electromagnetically induced transparency and Autler-Townes splitting effects is investigated theoretically. It is found that the optimal squeezing preservation of the outgoing probe beam occurs in the strong-coupling-field regime rather than in the weakcoupling- field regime. In the weak-coupling-field regime, which was recently recognized as the electromagnetically induced transparency regime (Abi-Salloum T Y 2010 Phys. Rev. A 81 053836), the output amplitude noise is affected mainly by the atomic noise originating from the random decay process of atoms. While in the strong-coupling-field regime, defined as the Autler-Townes splitting regime, the output amplitude noise is affected mainly by the phase-toamplitude conversion noise. This is useful in improving the quality of the experiment for efficient quantum memory, and hence has an application in quantum information processing. [ABSTRACT FROM AUTHOR]

The Planck constant h is one of the most significant constants in quantum physics. Recently, the precision measurement of the value of h has been a hot issue due to its important role for the establishment of both a new SI and a revised fundamental physical constant system. Up to date, two approaches, the watt balance and counting atoms, have been employed to determine the Planck constant at a level of several parts in 108. In this paper, the principle and progress on precision measurement of the Planck constant using watt balance and counting atoms at national metrology institutes are reviewed. Further improvement in determining the Planck constant and possible developments of a revised physical constant system in future are discussed. [ABSTRACT FROM AUTHOR]