1,828 research outputs found
Fast ground-state cooling of mechanical resonator with time-dependent optical cavities
We propose a feasible scheme to cool down a mechanical resonator (MR) in a
three-mirror cavity optomechanical system with controllable external optical
drives. Under the Born-Oppenheimer (BO) approximation, the whole dynamics of
the mechanical resonator and cavities is reduced to that of a time-dependent
harmonic oscillator, whose effective frequency can be controlled through the
optical driving fields. The fast cooling of the MR can be realized by
controlling the amplitude of the optical drives. Significantly, we further show
that the ground-state cooling may be achieved via the three-mirror cavity
optomechanical system without the resolved sideband condition.Comment: Some references including our previous works on cooling of mechanical
resonators are added, and some typos are corrected in this new version.
Comments are welcom
Pulsed Laser Cooling for Cavity-Optomechanical Resonators
A pulsed cooling scheme for optomechanical systems is presented that is
capable of cooling at much faster rates, shorter overall cooling times, and for
a wider set of experimental scenarios than is possible by conventional methods.
The proposed scheme can be implemented for both strongly and weakly coupled
optomechanical systems in both weakly and highly dissipative cavities. We study
analytically its underlying working mechanism, which is based on
interferometric control of optomechanical interactions, and we demonstrate its
efficiency with pulse sequences that are obtained by using methods from optimal
control. The short time in which our scheme approaches the optomechanical
ground state allows for a significant relaxation of current experimental
constraints. Finally, the framework presented here can be used to create a rich
variety of optomechanical interactions and hence offers a novel, readily
available toolbox for fast optomechanical quantum control.Comment: 6 pages, 4 figure
Using dark modes for high-fidelity optomechanical quantum state transfer
In a recent publication [Y.D. Wang and A.A. Clerk, Phys. Rev. Lett. 108,
153603 (2012)], we demonstrated that one can use interference to significantly
increase the fidelity of state transfer between two electromagnetic cavities
coupled to a common mechanical resonator over a naive sequential-transfer
scheme based on two swap operations. This involved making use of a delocalized
electromagnetic mode which is decoupled from the mechanical resonator, a
so-called "mechanically-dark" mode. Here, we demonstrate the existence of a new
"hybrid" state transfer scheme which incorporates the best elements of the
dark-mode scheme (protection against mechanical dissipation) and the
double-swap scheme (fast operation time). Importantly, this new scheme also
does not require the mechanical resonator to be prepared initially in its
ground state. We also provide additional details on the previously-described
interference-enhanced transfer schemes, and provide an enhanced discussion of
how the interference physics here is intimately related to the optomechanical
analogue of electromagnetically-induced transparency (EIT). We also compare the
various transfer schemes over a wide range of relevant experimental parameters,
producing a "phase diagram" showing the the optimal transfer scheme for
different points in parameter space.Comment: 39 pages, 11 figures NJP 14 (Focus issue on Optomechanics
Atom-mirror cooling and entanglement using cavity Electromagnetically Induced Transparency
We investigate a hybrid optomechanical system comprised of a mechanical
oscillator and an atomic 3-level ensemble within an optical cavity. We show
that a suitably tailored cavity field response via Electromagnetically Induced
Transparency (EIT) in the atomic medium allows for strong coupling of the
mechanical mirror oscillations to the collective atomic ground-state spin. This
facilitates ground-state cooling of the mirror motion, quantum state mapping
and robust atom-mirror entanglement even for cavity widths larger than the
mechanical oscillator frequency
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