Using flow equations, equilibrium and non-equilibrium dynamics of a two-level
system are investigated, which couples via non-commuting components to two
independent oscillator baths. In equilibrium the two-level energy splitting is
protected when the TLS is coupled symmetrically to both bath. A critical
asymmetry angle separates the localized from the delocalized phase.
  On the other hand, real-time decoherence of a non-equilibrium initial state
is for a generic initial state faster for a coupling to two baths than for a
single bath.Comment: 22 pages, 9 figure

A. Cuccoli

Andreas Hackl

C. P. Slichter

Heiner Kohler

S. Kehrein

Stefan Kehrein

English

arXiv

Using flowequations and equilibrium and nonequilibrium dynamics of a two-level system (TLS) is investigated, which couples Ohmically via noncommuting components to two independent oscillator baths. In equilibrium, the two-level energy splitting is protected when the TLS is coupled symmetrically to both baths. A critical asymmetry angle separates the localized from the delocalized phase. Real-time decoherence of a nonequilibrium initial state is studied as well. The short-time dynamics exhibits initial slips on the scale of the cutoff frequency of the bath modes. Moreover, whereas for a single bath decay of coherence depends crucially on the chosen initial state, for a symmetric coupling to two baths this dependence vanishes

Kohler, Heiner

Hackl, Andreas

Kehrein, Stefan

GRO.publications

Nonequilibrium dynamics of a system with quantum frustration

Using flow equations and equilibrium and nonequilibrium dynamics of a two-level system (TLS) is investigated, which couples Ohmically via noncommuting components to two independent oscillator baths. In equilibrium, the two-level energy splitting is protected when the TLS is coupled symmetrically to both baths. A critical asymmetry angle separates the localized from the delocalized phase. Real-time decoherence of a nonequilibrium initial state is studied as well. The short-time dynamics exhibits initial slips on the scale of the cutoff frequency of the bath modes. Moreover, whereas for a single bath decay of coherence depends crucially on the chosen initial state, for a symmetric coupling to two baths this dependence vanishes. © 2013 American Physical Society.H.K. acknowledges financial support from the German Research council (DFG) with Grant No. Ko 3538/1-2 and from CSIC within the JAE-Doc program cofunded by the FSE (Fondo Social Europeo). A.H. acknowledges support by the David and Ellen Lee foundation.Peer Reviewe

Non-equilibrium dynamics of a system with Quantum Frustration

Abstract

Similar works

Full text

Available Versions

GRO.publications

Digital.CSIC

GRO.publications (Univ. Göttingen)

Crossref