Collective Quantum Fields

Hagen M. Kleinert

Ivan Andrić

Fei Wang, Xiangming Hu, Wenxing Shi +1 more

We show that it is possible to obtain continuous variable entanglement for four optical fields via phase-dependent electromagnetically induced transparency in a four-level system in double-$\ensuremath{\Lambda}$ configuration. Due to quantum interference, the four fields constitute two quantum beats, behave as a pair of collective modes, and experience high cross Kerr nonlinearities. As a result, entanglement occurs between the two collective modes and between any two individual fields from the different collective modes.

Xiu Zhang, Xiangming Hu, Xuehua Zhang +1 more

This paper proposes a novel form of multimode nonlinear interactions by using a near-resonantly dressed atomic ensemble in an optical cavity. Due to quantum interference, a pair of collective fields come into the bilinear interactions, whose strengths are proportional to the population difference between dressed states which are coupled to the collective fields. By such an interaction, it is possible to obtain perfect multimode squeezing and collective Einstein-Podolsky-Rosen (EPR) entanglement in the cavity output.

S. M. Chumakov, A. B. Klimov, J. J. Sánchez-Mondragón

Xiu Zhang

We shown that it is possible to produce a entangled one-atom dressed-state laser via atomic coherence effcets. For a V-type three-level atom embedded in a two-mode cavity, two applied fields induce a quantum-beat and the collective field comes into interaction. The stastics of the collective field is sub-Poissonian in the good cavity condition. The collective field intensity quantum noise reducetion produces the entanglement between two cavity fields.