Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment.

摘要

The dissociation of a 199Hg2 dimer prepares an entangled state of two spatially separated 199Hg atoms, each with nuclear spin 1/2, and with zero total electron and nuclear spin angular momenta. This is identical to the entangled state of the two spin 1/2 particles in Bohm's classic version of the EPR gedankenexperiment . An analysis of the rotational structure of the upsilon'=57←upsilon''=0 band of the D3S+u 1u ← X1S+g 0+g transition in Hg2 (natural abundance) is presented. The analysis of the fluorescence excitation spectrum using a dye laser gives the values of the constants Bupsilon'=57 and Bupsilon''=0 for the excited and ground electronic energy states involved in the transition, respectively. To increase the accuracy of the rotational constants and resolve the fine spectrum of the Hg2, a continuously tunable single longitudinal mode laser with ultra-narrow line-width is needed. Measurements using a narrow line-width alexandrite laser had been attempted and the values of Bupsilon'=57 and Bupsilon''=0 were determined. To improve the quality of the laser beam and hence the precision of the rotational constants, modifications have been made to the cavity of the alexandrite laser. This provides a possibility for further investigation.