Enhancement of quantum correlations between Rabi sidebands via dressed population transfer

Abstract

We analyse the effects of coherent or incoherent dressed population transfer on two-mode squeezing and continuous variable entanglement in four-wave mixing. Two cavity modes are generated from Rabi sidebands of dressed two-level atoms. A weak coherent or incoherent field couples one dressed state to an auxiliary excited state, from which the atoms decay to the other dressed state. This provides a two-step channel for dressed population transfer and reduces spontaneous emission into a squeeze-transformed mode that enters into an interaction with the dressed atoms. It is the reduction of spontaneous emission that leads to an enhancement of two-mode squeezing, whose degree is increased to 75% compared with 50% for the two-level case. This corresponds to a significant enhancement of the continuous variable entanglement.