5,417 research outputs found
Statistics of radiation at Josephson parametric resonance
Motivated by recent experiments, we study theoretically the full counting
statistics of radiation emitted below the threshold of parametric resonance in
a Josephson junction circuit. In contrast to most optical systems, a
significant part of emitted radiation can be collected and converted to an
output signal. This permits studying the correlations of the radiation.
To quantify the correlations, we derive a closed expression for full counting
statistics in the limit of long measurement times. We demonstrate that the
statistics can be interpreted in terms of uncorrelated bursts each encompassing
2N photons, this accounts for the bunching of the photon pairs produced in
course of the parametric resonance. We present the details of the burst rates.
In addition, we study the time correlations within the bursts and discuss
experimental signatures of the statistics deriving the frequency-resolved
cross-correlations.Comment: 12 pages, 7 figure
Existence of mesons after deconfinement
We investigate the possibility for a quark-antiquark pair to form a bound
state at temperatures higher than the critical one (), thus after
deconfinement. Our main goal is to find analytical criteria constraining the
existence of such mesons. Our formalism relies on a Schr\"{o}dinger equation
for which we study the physical consequences of both using the free energy and
the internal energy as potential term, assuming a widely accepted
temperature-dependent Yukawa form for the free energy and a recently proposed
nonperturbative form for the screening mass. We show that using the free energy
only allows for the 1S bottomonium to be bound above , with a dissociation
temperature around . The situation is very different with the
internal energy, where we show that no bound states at all can exist in the
deconfined phase. But, in this last case, quasi-bound states could be present
at higher temperatures because of a positive barrier appearing in the
potential.Comment: 14 pages, 3 figures; only the case T>T_c is discussed in v
Proposal for an optical laser producing light at half the Josephson frequency
We describe a superconducting device capable of producing laser light in the
visible range at half of the Josephson generation frequency with the optical
phase of the light locked to the superconducting phase difference. It consists
of two single-level quantum dots embedded into a p-n semiconducting
heterostructure and surrounded by a cavity supporting a resonant optical mode.
We study decoherence and spontaneous switching in the device.Comment: 4+3 pages, 3+1 figure
Effective electroweak Hamiltonian in the gradient-flow formalism
The effective electroweak Hamiltonian in the gradient-flow formalism is constructed for the current-current operators through next-to-next-to-leading-order QCD. The results are presented for two common choices of the operator basis. This allows for a consistent matching of perturbatively evaluated Wilson coefficients and nonperturbative matrix elements evaluated by lattice simulations on the basis of the gradient-flow formalism
Weakly Compact Generating and Shrinking Markusevic Bases
2000 Mathematics Subject Classification: 46B30, 46B03.It is shown that most of the well known classes of nonseparable Banach spaces related to the weakly compact generating can be characterized by elementary properties of the closure of the coefficient space of Markusevic bases for such spaces. In some cases, such property is then shared by all Markusevic bases in the space
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