854 research outputs found
Excitations and superfluidity in non-equilibrium Bose-Einstein condensates of exciton-polaritons
We present a generic model for the description of non-equilibrium
Bose-Einstein condensates, suited for the modelling of non-resonantly pumped
polariton condensates in a semiconductor microcavity. The excitation spectrum
and scattering of the non-equilibrium condensate with a defect are discussed.Comment: 4 pages, 2 figure
Dynamical decoupling and dynamical isolation in temporally modulated coupled pendulums
We theoretically study the dynamics of a pair of coupled pendulums subject to
a periodic temporal modulation of their oscillation frequency. Inspired from
analogous developments in quantum mechanics, we anticipate dynamical
localization and dynamical isolation effects, as well as the occurrence of
non-trivial coupling phases. Perspectives in the direction of studying
synthetic gauge fields in a classical mechanics context are outlined.Comment: 7 pages, 5 figure
Absence of Long-Range Coherence in the Parametric Emission from Photonic Wires
We analytically investigate the spatial coherence properties of the signal
emission from one-dimensional optical parametric oscillators. Because of the
reduced dimensionality, quantum fluctuations are able to destroy the long-range
phase coherence even far above threshold. The spatial decay of coherence is
exponential and, for realistic parameters of semiconductor photonic wires in
the strong exciton-photon coupling regime, it is predicted to occur on an
experimentally accessible length scale.Comment: 6 pages, 3 figure
Non-equilibrium quasi-condensates in reduced dimensions
We develop a generic phenomenological model to describe the fluctuations on
top of a non-equilibrium Bose-Einstein condensate. Analytic expressions are
obtained for the momentum distribution of the non-condensed cloud and for the
long-distance behavior of the spatial coherence in the different
dimensionalities. Comparison of our predictions with available experimental
data on condensates of exciton-polaritons and on surface-emitting planar laser
devices is finally made.Comment: 6 pages, 1 figur
Mechanical back-reaction effect of the dynamical Casimir emission
We consider an optical cavity enclosed by a freely moving mirror attached to
a spring and we study the quantum friction effect exerted by the dynamical
Casimir emission on the mechanical motion of the mirror. Observable signatures
of this simplest example of back-reaction effect are studied in both the
ring-down oscillations of the mirror motion and in its steady-state motion
under a monochromatic force. Analytical expressions are found in simple yet
relevant cases and compared to complete numerical solution of the master
equation. A circuit-QED device allowing for experimental observation of the
effect with state-of-the-art technology is proposed and theoretically
characterized.Comment: 18 pages, 7 figures; comments are welcom
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