Sumei Huang

Electromagnetically induced transparency in mechanical effects of light

We consider the dynamical behavior of a nanomechanical mirror in a high-quality cavity under the action of a coupling laser and a probe laser. We demonstrate the existence of the analog of electromagnetically induced transparency (EIT) in the output field at the probe frequency. Our calculations show explicitly the origin of EIT-like dips as well as the characteristic changes in dispersion from anomalous to normal in the range where EIT dips occur. Remarkably the pump-probe response for the optomechanical system shares all the features of the

Electromagnetically induced transparency from two-phonon processes in quadratically coupled membranes

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Entangling nanomechanical oscillators in a ring cavity by feeding squeezed light

system as discovered by Harris and collaborators.

Normal-mode splitting in a coupled system of a nanomechanical oscillator and a parametric amplifier cavity

We describe how electromagnetically induced transparency can arise in quadratically coupled optomechanical systems. Due to quadratic coupling, the underlying optical process involves a two-phonon process in an optomechanical system, and this two-phonon process makes the mean displacement, which plays the role of atomic coherence in traditional electromagnetically induced transparency (EIT), zero. We show how the fluctuation in displacement can play a role similar to atomic coherence and can lead to EIT-like effects in quadratically coupled optomechanical systems. We show how such effects can be studied using the existing optomechanical systems.

Enhancement of cavity cooling of a micromechanical mirror using parametric interactions

A scheme is presented for entangling two separated nanomechanical oscillators by injecting broad band squeezed vacuum light and laser light into the ring cavity. We work in the resolved sideband regime. We find that in order to obtain the maximum entanglement of the two oscillators, the squeezing parameter of the input light should be about 1. We report significant entanglement over a very wide range of power levels of the pump and temperatures of the environment.

Normal-mode splitting and antibunching in Stokes and anti-Stokes processes in cavity optomechanics: Radiation-pressure-induced four-wave-mixing cavity optomechanics

We study how an optical parametric amplifier inside the cavity can affect the normal-mode splitting behavior of the coupled movable mirror and the cavity field. We work in the resolved sideband regime. The spectra exhibit a double-peak structure as the parametric gain is increased. Moreover, for a fixed parametric gain, the double-peak structure of the spectrum is more pronounced with increasing the input laser power. We give results for mode splitting. The widths of the split lines are sensitive to parametric gain.

Optomechanical Systems as Single Photon Routers

It is shown that an optical parametric amplifier inside a cavity can considerably improve the cooling of the micromechanical mirror by radiation pressure. The micromechanical mirror can be cooled from room temperature 300 K to sub-Kelvin temperatures, which is much lower than what is achievable in the absence of the parametric amplifier. This is further illustrated in case of a precooled mirror, where one can reach millikelvin temperatures starting with about 1K. Our work demonstrates the fundamental dependence of radiation pressure effects on photon statistics.

Reactive-coupling-induced normal mode splittings in microdisk resonators coupled to waveguides

We study Stokes and anti-Stokes processes in cavity optomechanics in the regime of strong coupling. The Stokes and anti-Stokes signals exhibit prominently the normal-mode splitting. We report gain for the Stokes signal. We also report lifetime splitting when the pump power is less than the critical power for normal-mode splitting. The nonlinear Stokes processes provide a useful method for studying the strong-coupling regime of cavity optomechanics. We also investigate the correlations between the Stokes and the anti-Stokes photons produced spontaneously by the optomechanical system. At zero temperature, our nanomechanical system leads to the correlations between the spontaneously generated photons exhibiting photon antibunching and those violating the Cauchy-Schwartz inequality.

Weak value amplification of atomic cat states

We show how EIT in cavity optomechanical systems can be used to produce a switch for a probe field in a single photon Fock state using very low pumping powers of few microwatt.

Can reactive coupling beat motional quantum limit of nano waveguides coupled to microdisk resonator

We study the optomechanical design introduced by M. Li et al. [Phys. Rev. Lett. 103, 223901 (2009)], which is very effective for investigation of the effects of reactive coupling. We show the normal mode splitting that is due solely to reactive coupling rather than due to dispersive coupling. We suggest feeding the waveguide with a pump field along with a probe field and scanning the output probe for evidence of reactive-coupling-induced normal mode splitting.