Dynamics of the spin-boson model: the effect of bath initial conditions

Abstract

Dynamics of the (sub-)Ohmic spin-boson model under various bath initial conditions is investigated by employing the Dirac-Frenkel time-dependent variational approach with the multiple Davydov ${\mathrm{D}}_1$ ansatz in the interaction picture. The validity of our approach is carefully checked by comparing results with those of the hierarchy equations of motion method. By analyzing the features of nonequilibrium dynamics, we identify the phase diagrams for different bath initial conditions. We find that for spectral exponent $s<s_c$, there exists a transition from coherent to quasicoherent dynamics with increasing the coupling strengths. For $s_c<s\le 1$, the coherent to incoherent crossover occurs at a certain coupling strength, and the quasicoherent dynamics emerges at much larger couplings. The initial preparation of the bath has considerable influence on the dynamics.

arXiv comment9 pages

References in corpus (16)

• Quantum state engineering with Josephson-junction devices
• Manipulating the Quantum State of an Electrical Circuit
• Numerical Renormalization Group for Bosonic Systems and Application to the Subohmic Spin-Boson Model
• Low- and high-frequency noise from coherent two-level systems
• The quantum phase transition in the sub-ohmic spin-boson model: Quantum Monte-Carlo study with a continuous imaginary time cluster algorithm
• Sparse polynomial space approach to dissipative quantum systems: Application to the sub-ohmic spin-boson model
• Non-Markovian decoherence of localized nanotube excitons by acoustic phonons
• Persistence of coherent quantum dynamics at strong dissipation
• Crossover from nonadiabatic to adiabatic electron transfer reactions: Multilevel blocking Monte Carlo simulations
• Variational dynamics of the sub-Ohmic spin-boson model on the basis of multiple Davydov ${\mathrm{D}}_1$ states
• Ultraslow quantum dynamics in a sub-Ohmic heat bath
• Dissipation due to two-level systems in nano-mechanical devices
• The Hidden Phase of the Spin-Boson Model
• Positive- and negative-frequency noise from an ensemble of two-level fluctuators
• Dynamics of quantum coherences at strong coupling to a heat bath
• Uncovering nonperturbative dynamics of the biased sub-Ohmic spin-boson model with variational Matrix Product States

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• Transient Dynamical Phase Diagram of the Spin-Boson Model at Finite Temperature