1,877 research outputs found
Feedback control of variable conductance heat pipes
Feedback system monitors source temperature and makes necessary changes of area available for heat rejection by adjusting storage volume of noncondensible gas and position of vapor/gas interface
Quantum optical master equation for solid-state quantum emitters
We provide an elementary description of the dynamics of defect centers in
crystals in terms of a quantum optical master equation which includes
spontaneous decay and a simplified vibronic interaction with lattice phonons.
We present the general solution of the dynamical equation by means of the
eigensystem of the Liouville operator and exemplify the usage of this damping
basis to calculate the dynamics of the electronic and vibrational degrees of
freedom and to provide an analysis of the spectra of scattered light. The
dynamics and spectral features are discussed with respect to the applicability
for color centers, especially for negatively charged nitrogen-vacancy centers
in diamond.Comment: 13 pages, 4 figure
Cooling the motion of a trapped atom with a cavity field
We theoretically analyze the cooling dynamics of an atom which is tightly
trapped inside a high-finesse optical resonator. Cooling is achieved by
suitably tailored scattering processes, in which the atomic dipole transition
either scatters a cavity photon into the electromagnetic field external to the
resonator, or performs a stimulated emission into the cavity mode, which then
dissipates via the cavity mirrors. We identify the parameter regimes in which
the atom center-of-mass motion can be cooled into the ground state of the
external trap. We predict, in particular, that for high cooperativities
interference effects mediated by the atomic transition may lead to higher
efficiencies. The dynamics is compared with the cooling dynamics of a trapped
atom inside a resonator studied in [Phys. Rev. Lett. 95, 143001, (2005)] where
the atom, instead of the cavity, is driven by a laser field
Thermalized non-equilibrated matter and high temperature superconducting state in quantum many-body systems
A characteristic feature of thermalized non-equilibrated matter is that, in
spite of energy relaxation--equilibration, a phase memory of the way the
many-body system was excited remains. As an example, we analyze data on a
strong forward peaking of thermal proton yield in the Bi(,p)
photonuclear reaction. New analysis shows that the phase relaxation in
highly-excited heavy nuclei can be 8 orders of magnitude or even much longer
than the energy relaxation. We argue that thermalized non-equilibrated matter
resembles a high temperature superconducting state in quantum many-body
systems. We briefly present results on the time-dependent correlation function
of the many-particle density fluctuations for such a superconducting state. It
should be of interest to experimentally search for manifestations of
thermalized non-equilibrated matter in many-body mesoscopic systems and
nanostructures.Comment: 12 pages, 1 eps figure. To be published in Radiation Effects and
Defects in Solid
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