Dynamics, Synchronization and Quantum Phase Transitions of Two Dissipative Spins
Abstract
We analyze the static and dynamical 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 subohmic bath using a combination of bosonic numerical renormalization group (NRG), analytical techniques and intuitive arguments. Second, 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 non-perturbative numerical results by exact analytical solutions when available and provide quantitative limits on the applicability of the perturbative Bloch-Redfield approach at weak coupling.
Cite
@article{arxiv.1007.2857,
title = {Dynamics, Synchronization and Quantum Phase Transitions of Two Dissipative Spins},
author = {Peter P. Orth and David Roosen and Walter Hofstetter and Karyn Le Hur},
journal= {arXiv preprint arXiv:1007.2857},
year = {2010}
}
Comments
21 pages, 18 figures