Spin two-axis-twisting via coherent population trapping based cavity QED

Abstract We present a spin two-axis-twisting mechanism via coherent population trapping (CPT) based atom–photon interactions. CPT happens and the atoms are trapped in dark state (coherent superposition of two ground states) when states resonantly coupled to common excited state. Close CPT, behave as dark-state spins, which interact with cavity vacuum fields. The otherwise nonexistent interaction is created between them identified be responsible for spin. essential difference from previous schemes compatibility twisting squeezing resonant atom-light interaction. unit serves kind new ingredients quantum networks.