2,545 research outputs found
Ultra-cold mechanical resonators coupled to atoms in an optical lattice
We propose an experiment utilizing an array of cooled micro-cantilevers
coupled to a sample of ultra-cold atoms trapped near a micro-fabricated
surface. The cantilevers allow individual lattice site addressing for atomic
state control and readout, and potentially may be useful in optical lattice
quantum computation schemes. Assuming resonators can be cooled to their
vibrational ground state, the implementation of a two-qubit controlled-NOT gate
with atomic internal states and the motional states of the resonator is
described. We also consider a protocol for entangling two or more cantilevers
on the atom chip with different resonance frequencies, using the trapped atoms
as an intermediary. Although similar experiments could be carried out with
magnetic microchip traps, the optical confinement scheme we consider may
exhibit reduced near-field magnetic noise and decoherence. Prospects for using
this novel system for tests of quantum mechanics at macroscopic scales or
quantum information processing are discussed.Comment: 5 pages, 3 figure
Clinical and functional comparison between different surgical approaches to total hip arthroplasty
Zeptonewton force sensing with nanospheres in an optical lattice
Optically trapped nanospheres in high-vaccum experience little friction and
hence are promising for ultra-sensitive force detection. Here we demonstrate
measurement times exceeding seconds and zeptonewton force sensitivity
with laser-cooled silica nanospheres trapped in an optical lattice. The
sensitivity achieved exceeds that of conventional room-temperature solid-state
force sensors, and enables a variety of applications including electric field
sensing, inertial sensing, and gravimetry. The optical potential allows the
particle to be confined in a number of possible trapping sites, with precise
localization at the anti-nodes of the optical standing wave. By studying the
motion of a particle which has been moved to an adjacent trapping site, the
known spacing of the lattice anti-nodes can be used to calibrate the
displacement spectrum of the particle. Finally, we study the dependence of the
trap stability and lifetime on the laser intensity and gas pressure, and
examine the heating rate of the particle in high vacuum in the absence of
optical feedback cooling.Comment: 5 pages, 4 figures, minor changes, typos corrected, references adde
Short-range force detection using optically-cooled levitated microspheres
We propose an experiment using optically trapped and cooled dielectric
microspheres for the detection of short-range forces. The center-of-mass motion
of a microsphere trapped in vacuum can experience extremely low dissipation and
quality factors of , leading to yoctonewton force sensitivity.
Trapping the sphere in an optical field enables positioning at less than 1
m from a surface, a regime where exotic new forces may exist. We expect
that the proposed system could advance the search for non-Newtonian gravity
forces via an enhanced sensitivity of over current experiments at
the 1 m length scale. Moreover, our system may be useful for
characterizing other short-range physics such as Casimir forces.Comment: 4 pages, 3 figures, minor changes, Figs. 1 and 2 replace
- …