84 research outputs found
A Molecular Matter-Wave Amplifier
We describe a matter-wave amplifier for vibrational ground state molecules,
which uses a Feshbach resonance to first form quasi-bound molecules starting
from an atomic Bose-Einstein condensate. The quasi-bound molecules are then
driven into their stable vibrational ground state via a two-photon Raman
transition inside an optical cavity. The transition from the quasi-bound state
to the electronically excited state is driven by a classical field.
Amplification of ground state molecules is then achieved by using a strongly
damped cavity mode for the transition from the electronically excited molecules
to the molecular ground state
Laser phase noise effects on the dynamics of optomechanical resonators
We investigate theoretically the influence of laser phase noise on the
cooling and heating of a generic cavity optomechanical system. We derive the
back-action damping and heating rates and the mechanical frequency shift of the
radiation pressure-driven oscillating mirror, and derive the minimum phonon
occupation number for small laser linewidths. We find that in practice laser
phase noise does not pose serious limitations to ground state cooling. We then
consider the effects of laser phase noise in a parametric cavity driving scheme
that minimizes the back-action heating of one of the quadratures of the
mechanical oscillator motion. Laser linewidths narrow compared to the decay
rate of the cavity field will not pose any problems in an experimental setting,
but broader linewidths limit the practicality of this back-action evasion
method.Comment: 9 pages, 7 figure
Role reversal in a Bose-condensed optomechanical system
We analyze the optomechanics-like properties of a Bose-Einstein condensate
(BEC) trapped inside an optical resonator and driven by both a classical and a
quantized light field. We find that this system exhibits a nature of role
reversal between the matter-wave field and the quantized light field. As a
result, the matter wave field now plays the role of the quantized light field,
and the quantized light field behaves like a movable mirror, in contrast to the
familiar situation in BEC-based cavity optomechanics [Brennecke et al., Science
322, 235 (2008); Murch et al., Nat. Phys. 4, 561 (2008)]. We demonstrate that
this system can lead to the creation of a variety of nonclassical matter-wave
fields, in particular cat states, and discuss several possible protocols to
measure their Wigner function
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