WP1: I introduced a double cavity sharing a common mechanical oscillator system where negative radiation pressure coupling between the cavity field and the end mirror is observed [1]. The measurement is performed by sending a two-mode squeezed vacuum to both cavities and detecting the output through heterodyne detection. Compared to the previously proposed schemes, I show that our scheme is capable of suppressing both the quantum noises with more
efficiency. It suppresses shot noise in the same amount and back action noise more efficiently that acts in lower frequencies (<100 Hz), which is more interesting to the community. In addition, the scheme has also proven to be beneficial for reducing thermal noise by a significant amount. The scheme consists of introducing a double cavity with end mirrors interlocked by a pivot and moving in opposite directions.
WP2: I show how to squeeze mechanical motion and entangle the optical field with mechanical motion in an optomechanical system containing a parametric amplification [2]. The scheme is based on optical bistability which emerges in the system for a strong enough driving field. When the steady
state is on the upper branch of the bistable shape, both squeezing and entanglement are greatly enhanced. Regarding the mechanical squeezing, it reaches the standard quantum limit (SQL) in the upper branch of the bistability. Our proposal provides a way to improve quantum effects in optomechanical systems by taking advantage of nonlinearities.
WP3: While studying the impact of filters on the two-mode hybrid squeezing, we consider both the distinct thermalization scenarios, i.e. one occurring in the vacuum state before entering the nonlinear crystal for squeezing and another after the generation of the two-mode squeezed vacuum but before passing through filters and detectors [3,4]. Both entanglement and nonlocality reach their peak when the filters are identical. However, increasing the degree of input squeezing while applying non-identical filters disrupts both entanglement and non-locality, leading to a bell-shaped pattern. Additionally, I provided precise boundaries for entanglement and non-locality. Combined with the filter, the population of two-mode squeezed thermal light influences the angle of a maximally squeezed hybrid quadrature.
