290 research outputs found
Reaction-diffusive dynamics of number-conserving dissipative quantum state preparation
The use of dissipation for the controlled creation of nontrivial quantum
many-body correlated states is of much fundamental and practical interest. What
is the result of imposing number conservation, which, in closed system, gives
rise to diffusive spreading? We investigate this question for a paradigmatic
model of a two-band system, with dissipative dynamics aiming to empty one band
and to populate the other, which had been introduced before for the dissipative
stabilization of topological states. Going beyond the mean-field treatment of
the dissipative dynamics, we demonstrate the emergence of a diffusive regime
for the particle and hole density modes at intermediate length- and
time-scales, which, interestingly, can only be excited in nonlinear response to
external fields. We also identify processes that limit the diffusive behavior
of this mode at the longest length- and time-scales. Strikingly, we find that
these processes lead to a reaction-diffusion dynamics governed by the
Fisher-Kolmogorov-Petrovsky-Piskunov equation, making the designed dark state
unstable towards a state with a finite particle and hole density.Comment: 25 pages, 11 figure
Reaction-diffusive dynamics of number-conserving dissipative quantum state preparation
The use of dissipation for the controlled creation of nontrivial quantum many-body correlated states is of much fundamental and practical interest. What is the result of imposing number conservation, which, in closed system, gives rise to diffusive spreading? We investigate this question for a paradigmatic model of a two-band system, with dissipative dynamics aiming to empty one band and to populate the other, which had been introduced before for the dissipative stabilization of topological states. Going beyond the mean-field treatment of the dissipative dynamics, we demonstrate the emergence of a diffusive regime for the particle and hole density modes at intermediate length- and time-scales, which, interestingly, can only be excited in nonlinear response to external fields. We also identify processes that limit the diffusive behavior of this mode at the longest length- and time-scales. Strikingly, we find that these processes lead to a reaction-diffusion dynamics governed by the Fisher-Kolmogorov-Petrovsky-Piskunov equation, making the designed dark state unstable towards a state with a finite particle and hole density
Quantum cavitation in liquid He: dissipation effects
We have investigated the effect that dissipation may have on the cavitation
process in normal liquid He. Our results indicate that a rather small
dissipation decreases sizeably the quantum-to-thermal crossover temperature
for cavitation in normal liquid He. This is a possible explanation
why recent experiments have not yet found clear evidence of quantum cavitation
at temperatures below the predicted by calculations which neglect
dissipation.Comment: To be published in Physical Review B6
Two-dimensional electron liquid with disorder in a weak magnetic field
We present the effective theory for low energy dynamics of a two-dimensional
interacting electrons in the presence of a weak short-range disorder and a weak
perpendicular magnetic field, the filling factor . We investigate
the exchange enhancement of the -factor, the effective mass and the decay
rate of the simplest spin wave excitations at . We obtain the
enhancement of the field-induced gap in the tunneling density of states and
dependence of the tunneling conductivity on the applied bias.Comment: 17 pages, no figure
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