Generation of coherent microwave radiation in a three level lambda system

A. R. Mkhitaryan

S. B. Grossman

Bryan J. Dalton, P. L. Knight

We demonstrate that atomic superposition states are sensitive to phase-dependent properties of radiation fields and that atoms prepared in such states can be employed as detectors. We concentrate on three-level detectors in two configurations, \ensuremath{\lambda} and ladder systems. \ensuremath{\lambda} systems prepared in a superposition state are shown to be sensitive to the relative phase between field modes and are relevant to measurements of fields produced by correlated-emission lasers. Ladder systems prepared in a superposition state are sensitive to the overall field phase and are relevant to measurements of fields generated in squeezing experiments. Such atomic-superposition-state detectors could be of value in detecting phase-dependent properties of microwave radiation in Rydberg atom masers and for investigating the properties of optical radiation generated in correlated-emission lasers.

Saesun Kim, Alberto M. Marino

Igor Bargatin, B. A. Grishanin, Victor N. Zadkov

We explore the possibilities of creating radiatively stable entangled states of two three-level dipole-interacting atoms in a \ensuremath{\Lambda} configuration by means of laser biharmonic continuous driving or pulses. We propose three schemes for generation of entangled states which involve only the lower states of the \ensuremath{\Lambda} system, not vulnerable to radiative decay. Two of them employ coherent dynamics to achieve entanglement in the system, whereas the third one uses optical pumping, i.e., an essentially incoherent process.

Guangling Cheng, Ai-Xi Chen, Wenxue Zhong

We present an alternative scheme for the generation of the entangled microwave radiation with amplification in single triple-Λ five-level molecular magnets driven by two strong control fields and one relative weak pump field. By numerically simulating the dynamics of the system, we show that three fully entangled modes with different frequencies can be obtained in the presence of the relaxations. Our numerical results also show that the entanglement occurs among the three cavity fields with a large number of photons. Physically, the responsible mechanism is quantum coherence. Two strong control fields induce two cavity modes coupled with the strong-driven levels to a quantum beat, and then the relative weak pump field leads to the parametric interaction between such a beat with the third mode coupled with the weak-driven level. The present work provides an efficient approach to achieve tripartite continuous-variable entanglement in the molecular magnets system, which may be necessary for the progress of solid-state quantum information.