8 research outputs found
Continuous variable entanglement by radiation pressure
We show that the radiation pressure of an intense optical field impinging on
a perfectly reflecting vibrating mirror is able to entangle in a robust way the
first two optical sideband modes. Under appropriate conditions, the generated
entangled state is of EPR type [A. Einstein, {\it et al.}, Phys. Rev. {\bf 47},
777 (1935)].Comment: 11 pages, 3 figure
Quantum noise in the position measurement of a cavity mirror undergoing Brownian motion
We perform a quantum theoretical calculation of the noise power spectrum for
a phase measurement of the light output from a coherently driven optical cavity
with a freely moving rear mirror. We examine how the noise resulting from the
quantum back action appears among the various contributions from other noise
sources. We do not assume an ideal (homodyne) phase measurement, but rather
consider phase modulation detection, which we show has a different shot noise
level. We also take into account the effects of thermal damping of the mirror,
losses within the cavity, and classical laser noise. We relate our theoretical
results to experimental parameters, so as to make direct comparisons with
current experiments simple. We also show that in this situation, the standard
Brownian motion master equation is inadequate for describing the thermal
damping of the mirror, as it produces a spurious term in the steady-state phase
fluctuation spectrum. The corrected Brownian motion master equation [L. Diosi,
Europhys. Lett. {\bf 22}, 1 (1993)] rectifies this inadequacy.Comment: 12 pages revtex, 2 figure
Mirror quiescence and high-sensitivity position measurements with feedback
We present a detailed study of how phase-sensitive feedback schemes can be
used to improve the performance of optomechanical devices. Considering the case
of a cavity mode coupled to an oscillating mirror by the radiation pressure, we
show how feedback can be used to reduce the position noise spectrum of the
mirror, cool it to its quantum ground state, or achieve position squeezing.
Then, we show that even though feedback is not able to improve the sensitivity
of stationary position spectral measurements, it is possible to design a
nonstationary strategy able to increase this sensitivity.Comment: 25 pages, 11 figure
Continuous variable entanglement and quantum state teleportation between optical and macroscopic vibrational modes through radiation pressure
We study an isolated, perfectly reflecting, mirror illuminated by an intense
laser pulse. We show that the resulting radiation pressure efficiently
entangles a mirror vibrational mode with the two reflected optical sideband
modes of the incident carrier beam. The entanglement of the resulting
three-mode state is studied in detail and it is shown to be robust against the
mirror mode temperature. We then show how this continuous variable entanglement
can be profitably used to teleport an unknown quantum state of an optical mode
onto the vibrational mode of the mirror.Comment: 18 pages, 10 figure