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Superfluid density of an open dissipative condensate
1SUPA, School of Physics and Astronomy, University of St. Andrews, KY16 9SS, United Kingdom.
Physical Review Letters
|September 21, 2011
Summary
Superfluid density persists in particle condensates with finite lifetimes, even without a Landau critical velocity. Dissipation reduces the superfluid fraction, and measurement methods for microcavity polaritons are proposed.
Area of Science:
- Quantum physics
- Condensed matter physics
Background:
- Superfluidity is a quantum mechanical phenomenon characterized by dissipationless flow.
- Nonequilibrium steady states (NESS) in quantum systems present unique challenges to understanding their properties.
- Finite-lifetime effects can significantly alter the behavior of quantum condensates.
Purpose of the Study:
- To calculate the superfluid density of a nonequilibrium steady state condensate.
- To investigate the survival of superfluid response in the presence of finite particle lifetimes and dissipation.
- To propose a measurement method for superfluid density in microcavity polaritons.
Main Methods:
- Theoretical calculation of superfluid density in a NESS.
- Analysis of the impact of finite particle lifetime on superfluid properties.
- Formulation of an experimental proposal for measuring superfluid density.
Main Results:
- A superfluid response is found to survive despite the absence of a simple Landau critical velocity.
- Dissipation demonstrably reduces the superfluid fraction.
- A method for measuring superfluid density in microcavity polaritons is suggested.
Conclusions:
- Superfluidity can exist in finite-lifetime condensates under nonequilibrium conditions.
- Dissipation plays a crucial role in diminishing the superfluid fraction.
- Experimental verification of these findings is feasible, particularly in systems like microcavity polaritons.
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