Clustering of polar molecules (SO2) in a supersonic jet was investigated by simulation. The cluster size Nc was calculated under different gas backing pressures P0 and source temperatures T0. Based on these results, the dependence of Nc on P0 or T0 was compared with that for the gases of non-polar molecules. It is found that SO2 molecules condense very easily into clusters even when P0 is very low. This result implies that large clusters can be produced using polar molecules, which could be useful in the studies of laser-cluster interactions. Also, SO2 gas is an important component of air pollution, so the knowledge of the clustering properties of SO2 could be helpful in the study of air pollution and environment.

Simulations of a polar molecule (sulfur dioxide) in a supersonic jet

The continuous-variable (CV) entanglement of the output fields is investigated in a four-level correlated emission laser system. The atomic coherence is introduced using two external classical driving fields. Based on the input–output theory, it is shown that the output entanglement and the entangled photons of the system can be achievable under certain conditions. Moreover, it is found that the two-mode entanglement has a close relation with the intensities of two external driving fields.

http://or.nsfc.gov.cn/bitstream/00001903-5/13990/1/1000007671010.pdf

Output entanglement in a four-level correlated emission laser

We investigate the continuous variable entanglement in a four-level atom according to the criterion proposed by Duan et al. [Phys. Rev. Lett. 84 (2000) 2722]. The atomic coherence is introduced using two external classical driving fields. We study the steady-state entanglement of the system in the presence of losses, concluding that the creation of entangled states can be achievable under certain conditions.

Chen Guang-Long

Papers

Two-Mode Steady-State Entanglement in a Four-Level Atomic System

Evolution of average cluster size in supsonic cluster jet under high gas backing pressure