Control of microwave signals using bichromatic electromechanically   induced transparency in three-mode circuit electromechanical systems
  We theoretically investigate the tunable slowing and advancing of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two mechanical oscillators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advance of 0.27 ms can be obtained in the current experiments. 
Cheng Jiang, Yuanshun Cui, Xiaowei Li
quant-ph