Robustness of the Gaussian interferometric power in two optomechanical systems

In two optomechanical systems, we study the robustness of the Gaussian interferometric power (GIP) against thermal noises. We use the Mancini et al. criterion to distinguish between entangled and separable states. Also, we employ the GIP to capture the nonclassical feature of the two studied systems beyond entanglement. We evaluate explicitly these two indicators of nonclassicality as functions of parameters characterizing the environment and the optomechanical systems (temperature, coupling, etc). We show that the inseparable quantum correlations decay strongly enough than those existing in separable states under thermal noises. On the other hand, when the separability criterion failed, the GIP remains almost constant and nonzero in the two systems even for high temperatures. This show that the GIP is an appropriate measure to capture the quantumness of correlations especially for systems coupled to environment strongly affected by thermal noises.