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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20191212T081312Z
UID:https://www.mpsd.mpg.de/events/18952/2724
DTSTART:20190612T123000Z
DTEND:20190612T140000Z
CLASS:PUBLIC
CREATED:20190606T123929Z
DESCRIPTION:Driven-dissipative systems represent natural platforms to study
non-equilibrium phases. In the first part of the talk\, I will present som
e physical results for which both non-equilibrium conditions and interactio
ns are crucial. I will argue that a prototype model of correlated driven-di
ssipative lattice bosons\, relevant for upcoming generation of circuit QED
arrays experiments\, exhibits a phase transition where a finite frequency m
ode becomes unstable\, as an effect of quantum interactions and non-equilib
rium conditions. In the broken-symmetry phase the corresponding macroscopic
order parameter becomes non-stationary and oscillates in time without damp
ing\, thus breaking continuous time-translational symmetry. To get some mor
e insights on this transition\, I studied the spectral properties of Markov
ian driven-dissipative quantum systems using a Lehmann representation. Focu
sing on the nonlinear quantum Van der Pol oscillator as a paradigmatic exam
ple\, I showed that a sign constraint of spectral functions\, which is math
ematically exact for closed systems\, gets relaxed for open systems\; it is
eventually replaced by an interplay between dissipation and interactions.
In the last part of the talk\, I will finally discuss a new method to solve
quantum impurity models\, small interacting quantum systems coupled to a n
on-Markovian environment\, in presence of additional Markovian dissipation.
I will derive a Dyson equation for the time-evolution operator of the redu
ced density matrix and approximate its self-energy resuming only non-crossi
ng diagrams. I will test this approach on a simple problem of a fermionic i
mpurity.
LAST-MODIFIED:20190606T124053Z
LOCATION:CFEL (Bldg. 99)\, Room: Seminar Room O1.060
ORGANIZER:Michael Sentef
SUMMARY:MPSD Seminar: Correlated driven-dissipative systems
URL:https://www.mpsd.mpg.de/events/18952/2724
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