In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous variable entanglement for a system consisting of two non-interacting bosonic modes embedded in two independent thermal environments. By using the Peres-Simon necessary and sufficient criterion for separability of two-mode Gaussian states, we describe ...

We report the use of the photothermal actuation for the self-excitation of a selected vibration mode of a microcantilever in liquid. The gain of the positive feedback loop is adjusted in order to obtain a negative effective damping. In this regime, the amplitude noise is squeezed due to the nonlinear saturation of the system and the phase noise is largely reduced. The microcantilever vibration ...

In our preceding serial works, we have investigated the generation of higherorder atomic dipole squeezing (HOADS) in a high-Q micromaser cavity, discussing the effects of dynamic Stark shift, atomic damping, atomic coherence and nonlinear one-photon processes and different initial states (for example, correlated and uncorrelated states, superposition states, squeezed vacuum). In this paper, we ...

We study entanglement and squeezing of a cluster of spin systems under the influence of the two-axis countertwisting Hamiltonian. The squeezing parameters given by Wineland et al and also by Kitagawa et al. are chosen as the criteria of spin squeezing. The criterion of pairwise entanglement is chosen to be the concurrence and that of the bipartite entanglement the linear entropy. We also define...

Abstract The thermomechanical coupling in shape memory alloys (SMAs) provides an effective mechanism of vibration damping by a cyclic structural phase transition. Here, we present simulations for active SMA damper device based on polycrystalline film materials, which via the one‐way effect is exploited. We apply extension previously reported superelastic model, that combines transition state ki...

It has been predicted and experimentally demonstrated that by injecting squeezed light into an optomechanical device, it is possible to enhance the precision of a position measurement. Here, we present a fundamentally different approach where the squeezing is created directly inside the cavity by a nonlinear medium. Counterintuitively, the enhancement of the signal-to-noise ratio works by deamp...