2,221 research outputs found
Reversible Quantum Interface for Tunable Single-sideband Modulation
Using Electromagnetically Induced Transparency (EIT) in a Cesium vapor, we
demonstrate experimentally that the quantum state of a light beam can be mapped
into the long lived Zeeman coherences of an atomic ground state. Two
non-commuting variables carried by light are simultaneously stored and
subsequentely read-out, with no noise added. We compare the case where a
tunable single sideband is stored independently of the other one to the case
where the two symmetrical sidebands are stored using the same EIT transparency
window.Comment: 4 pages, 6 figure
Dynamics of a pulsed continuous variable quantum memory
We study the transfer dynamics of non-classical fluctuations of light to the
ground-state collective spin components of an atomic ensemble during a pulsed
quantum memory sequence, and evaluate the relevant physical quantities to be
measured in order to characterize such a quantum memory. We show in particular
that the fluctuations stored into the atoms are emitted in temporal modes which
are always different than those of the readout pulse, but which can
nevertheless be retrieved efficiently using a suitable temporal mode-matching
technique. We give a simple toy model - a cavity with variable transmission -
which accounts for the behavior of the atomic quantum memory.Comment: 6 pages, 5 figure
Defending the Public Domain—The First Amendment, the Copyright Power, and the Potential of \u3ci\u3eGolan v. Gonzales\u3c/i\u3e
High-sensitivity optical measurement of mechanical Brownian motion
We describe an experiment in which a laser beam is sent into a high-finesse
optical cavity with a mirror coated on a mechanical resonator. We show that the
reflected light is very sensitive to small mirror displacements. We have
observed the Brownian motion of the resonator with a very high sensitivity.Comment: 4 pages, 4 figures, RevTe
Entanglement storage in atomic ensembles
We propose to entangle macroscopic atomic ensembles in cavity using
EPR-correlated beams. We show how the field entanglement can be almost
perfectly mapped onto the long-lived atomic spins associated with the ground
states of the ensembles, and how it can be retrieved in the fields exiting the
cavities after a variable storage time. Such a continuous variable quantum
memory is of interest for manipulating entanglement in quantum networks
Affect, Interpersonal Behaviour and Interpersonal Perception During Open-Label, Uncontrolled Paroxetine Treatment of People with Social Anxiety Disorder: A Pilot Study
Background: Laboratory-based research with community samples has suggested changes in affective, behavioural and cognitive processes as possible explanations for the effects of serotonergic medications. Examining the effects of serotonergic medications using an ecological momentary measure (such as event-contingent recording) in the daily lives of people with social anxiety disorder would contribute to establishing the effects of these medications on affect, behaviour and one form of cognition: perception of others’ behaviour.
Methods: The present study assessed changes in affect, interpersonal behaviour and perception of others’ behaviour in adults with social anxiety disorder using ecological momentary assessment at baseline and over 4 months of a single-arm, uncontrolled, open-label trial of treatment with the selective serotonin reuptake inhibitor paroxetine.
Results: Anxiety and concurrent depressive symptoms decreased. Participants also reported increased positive and decreased negative affect; increased agreeable and decreased quarrelsome behaviour; increased dominant and decreased submissive behaviour; and increased perception that others behaved agreeably toward them. Moreover, participants demonstrated reduced intraindividual variability in affect, interpersonal behaviour and perception of others’ behaviour.
Limitations: Limitations included the lack of a placebo group, the inability to identify the temporal order of changes and the restricted assessment of extreme behaviour.
Conclusion: The results of the present study demonstrate changes during pharmacotherapy in the manifestation of affect, interpersonal behaviour and interpersonal perception in the daily lives of people with social anxiety disorder. Given the importance of interpersonal processes to social anxiety disorder, these results may guide future research seeking to clarify mechanisms of action for serotonergic medications
Selective readout and back-action reduction for wideband acoustic gravitational wave detectors
We present the concept of selective readout for broadband resonant mass
gravitational wave detectors. This detection scheme is capable of specifically
selecting the signal from the contributions of the vibrational modes sensitive
to the gravitational waves, and efficiently rejecting the contribution from non
gravitationally sensitive modes. Moreover this readout, applied to a dual
detector, is capable to give an effective reduction of the back-action noise
within the frequency band of interest. The overall effect is a significant
enhancement in the predicted sensitivity, evaluated at the standard quantum
limit for a dual torus detector. A molybdenum detector, 1 m in diameter and
equipped with a wide area selective readout, would reach spectral strain
sensitivities 2x10^{-23}/sqrt{Hz} between 2-6 kHz.Comment: 9 pages, 4 figure
Long-lived quantum memory with nuclear atomic spins
We propose to store non-classical states of light into the macroscopic
collective nuclear spin ( atoms) of a He vapor, using
metastability exchange collisions. These collisions, commonly used to transfer
orientation from the metastable state to the ground state state of
He, can also transfer quantum correlations. This gives a possible
experimental scheme to map a squeezed vacuum field state onto a nuclear spin
state with very long storage times (hours).Comment: 4 page
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