Dynamics, synchronization, and quantum phase transitions of two dissipative spins

Journal Article · Fri Oct 01 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.82.144423· OSTI ID:21421454

Orth, Peter P; Le Hur, Karyn ^[1]; Roosen, David; Hofstetter, Walter ^[2]

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1. Department of Physics, Yale University, New Haven, Connecticut 06520 (United States)
2. Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet, 60438 Frankfurt/Main (Germany)

We analyze the static and dynamic properties of two Ising-coupled quantum spins embedded in a common bosonic bath as an archetype of dissipative quantum mechanics. First, we elucidate the ground-state phase diagram for an Ohmic and a sub-Ohmic bath using a combination of bosonic numerical renormalization group (NRG), analytical techniques, and intuitive arguments. Second, by employing the time-dependent NRG we investigate the system's rich dynamical behavior arising from the complex interplay between spin-spin and spin-bath interactions. Interestingly, spin oscillations can synchronize due to the proximity of the common non-Markovian bath and the system displays highly entangled steady states for certain nonequilibrium initial preparations. We complement our nonperturbative numerical results by exact analytical solutions when available and provide quantitative limits on the applicability of the perturbative Bloch-Redfield approach at weak coupling.

• OSTI ID: 21421454
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 14; Other Information: DOI: 10.1103/PhysRevB.82.144423; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANALYTICAL SOLUTION
COUPLING
GROUND STATES
INTERACTIONS
MARKOV PROCESS
OSCILLATIONS
PERTURBATION THEORY
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
QUANTUM ENTANGLEMENT
QUANTUM MECHANICS
RENORMALIZATION
SPIN
STEADY-STATE CONDITIONS
SYNCHRONIZATION
TIME DEPENDENCE
WEAK-COUPLING MODEL
ANGULAR MOMENTUM
DIAGRAMS
ENERGY LEVELS
INFORMATION
MATHEMATICAL MODELS
MATHEMATICAL SOLUTIONS
MECHANICS
NUCLEAR MODELS
PARTICLE PROPERTIES
STOCHASTIC PROCESSES