INVESTIGADORES
IUCCI Carlos Anibal
artículos
Título:
Effective temperature from fluctuation-dissipation theorem in systems with bipartite eigenmode entanglement
Autor/es:
T. BORTOLIN; A. IUCCI
Revista:
PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2015 vol. 91 p. 24301 - 999999999
ISSN:
1050-2947
Resumen:
In thermal equilibrium, the fluctuation-dissipation theorem relates the
linear response and correlation functions in a model and observable
independent fashion. Out of equilibrium, these relations still hold if
the equilibrium temperature is replaced by an observable and
frequency-dependent parameter (effective temperature). When the system
achieves a long-time thermal state all of these effective temperatures
should be equal and constant. Following this approach we examine the
long-times regime after a quantum quench in a system with bipartite
entanglement in which the asymptotic values of the observable are
compatible with the ones obtained in a Gibbs ensemble. We observe that
when the initial entanglement is large, and for a large range of
(intermediate) frequencies, the effective temperatures corresponding to
the analyzed local and nonlocal operators approach an approximate
constant value equal to the temperature that governs the decay of
correlations. Still, the residual frequency dependence in the effective
temperature, and the differences observed among observables, discards
strict thermalization.