Nonlinear parametric interaction and higher-order squeezing in coherent population trapping
1 College of Science, China Three Gorges University - Yichang, 443002, China
2 College of Physical Science and Technology, Central China Normal University - Wuhan, 430079, China
Received: 16 July 2014
Accepted: 25 November 2014
In this paper, we show that coherent population trapping (CPT) system can act as a nonlinear parametric interaction process, in which higher-order nonlinear effects are included, giving rise to the occurrence of nonclassical quantum correlation. Furthermore, our numerical results confirm that single- and two-mode higher-order squeezing are possible to obtain under different conditions because of the higher-order nonlinear effects, which are strongly determined by the atomic coherence. The higher-order squeezing obtained in CPT is robust against dissipation since the atoms are nearly trapped into the ground state, which may be useful for high-precision measurement.
PACS: 42.50.Gy – Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption / 32.80.Qk – Coherent control of atomic interactions with photons / 42.50.Lc – Quantum fluctuations, quantum noise, and quantum jumps
© EPLA, 2014