The Hidden Phase of the Spin-Boson Model

Abstract

A quantum two-level system immersed in a sub-Ohmic bath experiences enhanced low-frequency quantum statistical fluctuations which render the nonequilibrium quantum dynamics highly non-Markovian. Upon using the numerically exact time-evolving matrix product operator approach, we investigate the phase diagram of the polarization dynamics. In addition to the known phases of damped coherent oscillatory dynamics and overdamped decay, we identify a new third region in the phase diagram for strong coupling showing an aperiodic behaviour. We determine the corresponding phase boundaries. The dynamics of the quantum two-state system herein is not coherent by itself but slaved to the oscillatory bath dynamics.

References in corpus (3)

• Multiple energy scales at a quantum critical point
• Low- and high-frequency noise from coherent two-level systems
• Equilibrium and non-equilibrium dynamics of the sub-ohmic spin-boson model

Cited by in corpus (4)

• Real-time Impurity Solver Using Grassmann Time-Evolving Matrix Product Operators
• Path Integral Formalism for Quantum Open Systems
• Transient Dynamical Phase Diagram of the Spin-Boson Model at Finite Temperature
• Quantum criticality in sub-Ohmic systems with three competing terms: beyond conventional spin-boson physics