Quantum criticality in sub-Ohmic systems with three competing terms: beyond conventional spin-boson physics

Abstract

Quantum phase transitions (QPTs) in the spin-boson model with/without the rotating-wave approximation (RWA) are systematically investigated through variational calculations using a sub-Ohmic bath with high spectral density. Four cases involving different system-environment interactions are examined, where transition points and critical exponents are accurately determined across varying tunneling strengths. Contrary to prior work, a rich phase diagram is revealed in the tunneling-coupling plane even at the low spectral exponent $s<1/2$, with a novel U(1)-symmetric phase being identified. As coupling increases, a multi-stage QPT sequence arises for the tunneling $0<\Delta <{\Delta }^{\ast }=0.074(1)$, whereas a single transition occurs beyond this range. Furthermore, an odd-parity phase is found to emerge even under the positive tunneling, exhibiting distinct characteristics relative to the prototype model.

18 pages, 13 figures

References in corpus (51)

• Entanglement Entropy and Quantum Field Theory
• Continuous-time Monte Carlo methods for quantum impurity models
• Non-Markovian dynamics in open quantum systems
• Vibrations, Quanta and Biology
• Quantum Phase Transition and Universal Dynamics in the Rabi model
• Numerical Renormalization Group for Bosonic Systems and Application to the Subohmic Spin-Boson Model
• Numerical Renormalization Group for Quantum Impurities in a Bosonic Bath
• Momentum-space entanglement and renormalization in quantum field theory
• Universal scaling and critical exponents of the anisotropic quantum Rabi model
• The quantum phase transition in the sub-ohmic spin-boson model: Quantum Monte-Carlo study with a continuous imaginary time cluster algorithm
• Quantum phase transitions in the sub-ohmic spin-boson model: Failure of the quantum-classical mapping
• Spontaneous two photon emission from a single quantum dot
• Quantum Phase Transition in the Finite Jaynes-Cummings Lattice Systems
• Entanglement Entropy, decoherence, and quantum phase transition of a dissipative two-level system
• Critical and strong-coupling phases in one- and two-bath spin-boson models
• Anisotropic Rabi model
• A variational description of the quantum phase transition in the sub-Ohmic spin-boson model
• Probing the strongly driven spin-boson model in a superconducting quantum circuit
• Sparse polynomial space approach to dissipative quantum systems: Application to the sub-ohmic spin-boson model
• Cavity QED simulation of qubit-oscillator dynamics in the ultrastrong coupling regime
• Quantum Phase Transition in the Sub-Ohmic Spin-Boson Model: Extended Coherent-state Approach
• A generalized multi-polaron expansion for the spin-boson model: Environmental entanglement and the biased two-state system
• Universal features of left-right entanglement entropy
• Variational dynamics of the sub-Ohmic spin-boson model on the basis of multiple Davydov ${\mathrm{D}}_1$ states
• Quantum simulation of the spin-boson model with a microwave circuit
• Stabilizing Spin Coherence Through Environmental Entanglement in Strongly Dissipative Quantum Systems
• Quantum algorithms for quantum dynamics: A performance study on the spin-boson model
• Ground state and dynamics of the biased dissipative two-state system: Beyond variational polaron theory
• Programmable quantum simulations of bosonic systems with trapped ions
• The Hidden Phase of the Spin-Boson Model
• Quantum phase transition in the delocalized regime of the spin-boson model
• Ground state properties of sub-Ohmic spin-boson model with simultaneous diagonal and off-diagonal coupling
• Anatomy of quantum critical wave functions in dissipative impurity problems
• Symmetry and the critical phase of the two-bath spin-boson model: Ground-state properties
• Density matrix renormalization group approach of the spin-boson model
• The quantum phase transition and correlations in the multi-spin-boson model
• Universal spatial correlations in the anisotropic Kondo screening cloud: analytical insights and numerically exact results from a coherent state expansion
• Chiral entanglement in massive quantum field theories in 1+1 dimensions
• Variational study of two-impurity spin-boson model with a common Ohmic bath: Ground-state phase transitions
• Quantum Phase Transition of Many Interacting Spins Coupled to a Bosonic Bath: static and dynamical properties
• Matrix Product State Representation without explicit local Hilbert Space Truncation with Applications to the Sub-Ohmic Spin-Boson Model
• SU(2)-Symmetric Spin-Boson Model: Quantum Criticality, Fixed-Point Annihilation, and Duality
• Rich phase diagram of quantum phases in the anisotropic subohmic spin-boson model
• Quantum phase transitions in the spin-boson model without the counterrotating terms
• Improved Silbey-Harris polaron ansatz for the spin-boson model
• Unveiling quantum entanglement and correlation of sub-Ohmic and Ohmic baths for quantum phase transitions in dissipative systems
• Fast quantum state preparation and bath dynamics using non-Gaussian variational ansatz and quantum optimal control
• Quantum criticality of the Ohmic spin-boson model in a high dense spectrum: symmetries,quantum fluctuations and correlations
• First-order transitions in spin chains coupled to quantum baths
• Anisotropic signatures in the spin-boson model
• Numerical variational simulations of quantum phase transitions in the sub-Ohmic spin-boson model with multiple polaron ansatz