Spin fluctuations in the dissipative phase transitions of the quantum Rabi model

• URL: http://arxiv.org/abs/2312.06376v1
• Date: Mon, 11 Dec 2023 13:35:05 GMT
• Title: Spin fluctuations in the dissipative phase transitions of the quantum Rabi model
• Authors: Jiahui Li, Rosario Fazio, Yingdan Wang, Stefano Chesi
• Abstract summary: We investigate the dissipative phase transitions of the anisotropic quantum Rabi model with cavity decay. Our findings indicate a general tendency of forming extreme non-equilibrium states in the single-spin system.
• Score: 0.998109397893173
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate the dissipative phase transitions of the anisotropic quantum Rabi model with cavity decay and demonstrate that large spin fluctuations persist in the stationary state, having important consequences on the phase diagram and the critical properties. In the second-order phase transition to the superradiant phase, there is a significant suppression of the order parameter and the appearance of non-universal factors, which directly reflect the spin populations. Furthermore, upon entering a parameter regime where mean-field theory predicts a tricritical phase, we find a first-order phase transition due to the unexpected collapse of superradiance. An accurate and physically transparent description going beyond mean-field theory is established by combining exact numerical simulations, the cumulant expansion, and analytical approximations based on reduced master equations and an effective equilibrium theory. Our findings, compared to the conventional thermodynamic limit of the Dicke model, indicate a general tendency of forming extreme non-equilibrium states in the single-spin system, thus have broad implications for dissipative phase transitions of few-body systems.

Related papers

• Probing quantum floating phases in Rydberg atom arrays [61.242961328078245]
  We experimentally observe the emergence of the quantum floating phase in 92 neutral-atom qubits. The site-resolved measurement reveals the formation of domain walls within the commensurate ordered phase. As the experimental system sizes increase, we show that the wave vectors approach a continuum of values incommensurate with the lattice.
  arXiv  Detail & Related papers  (2024-01-16T03:26:36Z)
• Multicritical dissipative phase transitions in the anisotropic open quantum Rabi model [0.7499722271664147]
  We investigate the nonequilibrium steady state of the anisotropic open quantum Rabi model. We find a rich phase diagram resulting from the interplay between the anisotropy and the dissipation. Our study enlarges the scope of critical phenomena that may occur in finite-component quantum systems.
  arXiv  Detail & Related papers  (2023-11-19T15:13:57Z)
• Dynamics Reflects Quantum Phase Transition of Rabi Model [0.0]
  A breakdown in the rotating wave approximation of the Rabi model leads to phase transition versus coupling strength. We show that the dynamics of physical quantities can reflect such a phase transition for this model. This work offers an idea to explore phase transitions by non-equilibrium process for open quantum systems.
  arXiv  Detail & Related papers  (2023-09-13T14:45:07Z)
• Quantum Effects on the Synchronization Dynamics of the Kuramoto Model [62.997667081978825]
  We show that quantum fluctuations hinder the emergence of synchronization, albeit not entirely suppressing it. We derive an analytical expression for the critical coupling, highlighting its dependence on the model parameters.
  arXiv  Detail & Related papers  (2023-06-16T16:41:16Z)
• Theory of the Loschmidt echo and dynamical quantum phase transitions in disordered Fermi systems [0.0]
  We develop the theory of the Loschmidt echo and dynamical phase transitions in non-interacting strongly disordered Fermi systems after a quench. In finite systems the Loschmidt echo displays zeros in the complex time plane that depend on the random potential realization. We show that this dynamical phase transition can be understood as a transition in the distribution function of the smallest eigenvalue of the Loschmidt matrix.
  arXiv  Detail & Related papers  (2022-09-22T10:04:45Z)
• Photoinduced prethermal order parameter dynamics in the two-dimensional large-$N$ Hubbard-Heisenberg model [77.34726150561087]
  We study the microscopic dynamics of competing ordered phases in a two-dimensional correlated electron model. We simulate the light-induced transition between two competing phases.
  arXiv  Detail & Related papers  (2022-05-13T13:13:31Z)
• Topological transitions with continuously monitored free fermions [68.8204255655161]
  We show the presence of a topological phase transition that is of a different universality class than that observed in stroboscopic projective circuits. We find that this entanglement transition is well identified by a combination of the bipartite entanglement entropy and the topological entanglement entropy.
  arXiv  Detail & Related papers  (2021-12-17T22:01:54Z)
• Entanglement Transitions from Stochastic Resetting of Non-Hermitian Quasiparticles [0.0]
  We write down a renewal equation for the statistics of the entanglement entropy and show that depending on the spectrum of quasiparticle decay rates different entanglement scaling can arise and even sharp entanglement phase transitions. When applied to a Quantum Ising chain where the transverse magnetization is measured by quantum jumps, our theory predicts a critical phase with logarithmic scaling of the entanglement, an area law phase and a continuous phase transition between them, with an effective central charge vanishing as a square root at the transition point.
  arXiv  Detail & Related papers  (2021-11-05T13:38:04Z)
• Superradiant phase transition in complex networks [62.997667081978825]
  We consider a superradiant phase transition problem for the Dicke-Ising model. We examine regular, random, and scale-free network structures.
  arXiv  Detail & Related papers  (2020-12-05T17:40:53Z)
• Universal dynamics of superradiant phase transition in the anisotropic quantum Rabi model [6.133109867277849]
  We investigate the universally non-equilibrium dynamics of superradiant phase transition in the anisotropic quantum Rabi model. We analytically extract the critical exponents from the excitation gap and the diverging length scale near the critical point.
  arXiv  Detail & Related papers  (2020-09-23T10:44:29Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.