Static synthetic gauge field control of double optomechanically induced transparency in a closed-contour interaction scheme

Abstract

We theoretically study an optical cavity and a PT -symmetric pair of mechanical resonators, where all oscillators are pairwise coupled, forming an optomechanical system with a closed-contour interaction. Due to the presence of both gain and feedback, we first explore its stability and the root loci over a large coupling range. Under the red-sideband pumping, and for the so-called PT unbroken phase it displays a double optomechanically induced transparency for an experimentally realizable parameter set. We show that both the transmission amplitude and the group delay can be continuously steered from lower transmission window to the upper one by the phase of the loop coupling parameter which acts as a static synthetic gauge field. In the PT -unbroken phase both the gain-bandwidth and delay-bandwidth products remain constant over the full range of the controlling phase. Tunability in transmission and bandwidth still prevails in the PT -broken phase. In essence, we suggest a simple scheme that grants coupling phase dependent control of the single and double OMIT phenomena within an effective PT -symmetric optomechanical system.