Abstract
A Bose gas in a double-well potential, exhibiting a true Bose-Einstein
condensate (BEC) amplitude and initially performing Josephson oscillations,
is a prototype of an isolated, non-equilibrium many-body system.
We investigate the quasiparticle creation and thermalization dynamics of
this system by solving the time-dependent Keldysh-Bogoliubov equations.
We find slow, exponential relaxation to a thermal state at an elevated temperature,
controlled by the initial excitation energy of the oscillating BEC
above its ground state. Interestingly, the relaxation is preceded by an effective decoupling of the quasiparticle subsystem from the BEC oscillations. The thermalization occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.
condensate (BEC) amplitude and initially performing Josephson oscillations,
is a prototype of an isolated, non-equilibrium many-body system.
We investigate the quasiparticle creation and thermalization dynamics of
this system by solving the time-dependent Keldysh-Bogoliubov equations.
We find slow, exponential relaxation to a thermal state at an elevated temperature,
controlled by the initial excitation energy of the oscillating BEC
above its ground state. Interestingly, the relaxation is preceded by an effective decoupling of the quasiparticle subsystem from the BEC oscillations. The thermalization occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.
Original language | English |
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Article number | 225304 |
Pages (from-to) | 1-5 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 116 |
Issue number | 22 |
DOIs | |
Publication status | Published - 2 Jun 2016 |