444 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
Resonant interaction of trapped cold atoms with a magnetic cantilever tip
Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited
using a micro- cantilever with a magnetic tip. The cantilever is mounted on a
multi-layer chip designed to capture, cool, and magnetically transport cold
atoms. The coupling is observed by measuring the loss from a magnetic trap as
the oscillating cantilever induces Zeeman state transitions in the atoms.
Interfacing cold atoms with mechanical devices could enable probing and
manipulating atomic spins with nanometer spatial resolution and single-spin
sensitivity, leading to new capabilities in quantum computation, quantum
simulation, or precision sensing.Comment: 5 pages, 4 figure
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
Improved constraints on non-Newtonian forces at 10 microns
Several recent theories suggest that light moduli or particles in "large"
extra dimensions could mediate macroscopic forces exceeding gravitational
strength at length scales below a millimeter. Such new forces can be
parameterized as a Yukawa-type correction to the Newtonian potential of
strength relative to gravity and range . To extend the search
for such new physics we have improved our apparatus utilizing cryogenic
micro-cantilevers capable of measuring attonewton forces, which now includes a
switchable magnetic force for calibration. Our most recent experimental
constraints on Yukawa-type deviations from Newtonian gravity are more than
three times as stringent as our previously published results, and represent the
best bound in the range of 5 - 15 microns, with a 95 percent confidence
exclusion of forces with at = 10 microns.Comment: 12 pages, 9 figures, accepted for publication in PRD. Minor changes,
replaced and corrected Figs 4,5,
New species of Cheumatopsyche (Trichoptera: Hydropsychidae) from North Sulawesi, Indonesia
Sulawesi Island has a high density of endemic animal species, including insects in the order Trichoptera. We describe the males of four new species of Cheumatopsyche (Trichoptera: Hydropsychidae) from North Sulawesi (Provinsi Sulawesi Utara), and provide a checklist of the Cheumatopsyche species from the Indonesian archipelago. Describing the aquatic insect fauna is an important step toward establishing biomonitoring protocols in Indonesia, which is experiencing rapid development and water pollution problems
The Promethean: Spring 2012
Spring 2012 edition of The Promethean.
Contents:
From the Director 2 Editors Farewell 4 Alumnus Looks Back 6 âWhy I Teach Honorsâ 7 âI Love the 90sâ Party 8 Art and Poetry 9https://digitalcommons.brockport.edu/promethean/1008/thumbnail.jp
The Promethean: Fall 2011
Fall 2011 edition of The Promethean.
Contents:
From The Director 2, Dr. Banerjee Returns 5, Summer of Beekeeping 7, Whatâs In Your Food? 8, Mentor vs. Mentee Experiences 9, Art and Poetry 11.https://digitalcommons.brockport.edu/promethean/1010/thumbnail.jp
Defining the Genus Hydropsyche (Trichoptera:Hydropsychidae) Based on DNA and Morphological Evidence
In this paper, we review the history of Hydropsychinae genus-level classification and nomenclature and present new molecular evidence from mitochondrial cytochrome c oxidase subunit I (COI) and nuclear large subunit ribosomal ribonucleic acid (28S) markers supporting the monophyly of the genus Hydropsyche. Both molecular and morphological characters support a broad conservative definition of Hydropsyche. Caledopsyche, Hydatomanicus, and Occutanspsyche are synonymized with Hydropsyche. The following species groups are established: Hydropsyche bronta Group (generally corresponding with Ceratopsyche and Hydropsyche morosa and newae Groups), Hydropsyche colonica Group (generally corresponding with Orthopsyche), Hydropsyche instabilis Group (generally corresponding with Hydropsyche s.s.), and Hydropsyche naumanni Group (generally corresponding with Occutanspsyche). Molecular data recovered Hydromanicus as paraphyletic, and Cheumatopsyche and Potamyia as sister taxa. The genus names Plectropsyche and Streptopsyche are reinstated
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