Complexity transition in the Dicke model of light-matter interaction

• URL: http://arxiv.org/abs/2607.21583v1
• Date: Thu, 23 Jul 2026 17:57:15 GMT
• Title: Complexity transition in the Dicke model of light-matter interaction
• Abstract summary: tuning the coupling strength $g$ of an interacting quantum system may drive a sudden change in its ground-state or thermal properties.<n>We present evidence for such a transition by mapping out the complexity phase diagram of the paradigmatic Dicke model.<n>We elucidate the nature of the regime change from the wave packet dynamics in Krylov space, where a particle is confined by a roughly linear potential but hops as if it lives in a Rindler reference frame.
• Score: 4.342189319523322
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Tuning the coupling strength $g$ of an interacting quantum system may drive a sudden change in its ground-state or thermal properties. To identify and grasp non-analytical, or even discontinuous, transitions in far-from-equilibrium dynamics proves more challenging. Recently Krylov complexity $C_K$ has offered fresh insights about operator growth, thermalization, and chaos in quantum dynamics. Yet it remains unclear if, and how, changing $g$ can trigger a sharp transition in the complexity measures. Here we present evidence for such a transition by mapping out the complexity phase diagram of the paradigmatic Dicke model describing two-level atoms coupled to a cavity photon mode. Two qualitatively different regimes of dynamics are identified and characterized. At the transition, the slope of $C_K$ changes suddenly to coincide with a jump in the Krylov entropy. We elucidate the nature of the regime change from the wave packet dynamics in Krylov space, where a particle is confined by a roughly linear potential but hops as if it lives in a Rindler reference frame. The competition between confinement, which leads to bouncing, and deconfinement by Rindler hopping, which leads to the destruction of wave packet analogous to gravitational spaghettification, is sensitive to the disorder in Lanczos coefficients. The framework outlined here can be applied to other quantum many-body systems.

Related papers

• Symmetry-protected topology and deconfined solitons in a multi-link $\mathbb{Z}_2$ gauge theory [45.88028371034407]
  We study a $mathbbZ$ lattice gauge theory defined on a multi-graph with links that can be visualized as great circles of a spherical shell.<n>We show that this leads to state-dependent tunneling amplitudes underlying a phenomenon analogous to the Peierls instability.<n>By performining a detailed analysis based on matrix product states, we prove that charge deconfinement emerges as a consequence of charge-fractionalization.
  arXiv  Detail & Related papers  (2026-03-02T22:59:25Z)
• Quantum simulation of the Dicke model in a two-dimensional ion crystal: chaos, quantum thermalization, and revivals [2.699606229706245]
  We realize the Dicke model -- a fundamental description of light-matter interactions -- in a two-dimensional crystal of 100 trapped ions.<n>Our results establish large ion crystals as scalable analog quantum simulators of non-equilibrium light-matter dynamics.
  arXiv  Detail & Related papers  (2026-02-05T19:00:01Z)
• Integrability Breaking and Coherent Dynamics in Hermitian and Non-Hermitian Spin Chains with Long-Range Coupling [0.0]
  We find a universal mechanism by which long-range and non-Hermitian effects reshape quantum ergodicity.<n>Our findings offer new pathways for preserving quantum coherence in complex many-body systems.
  arXiv  Detail & Related papers  (2025-12-16T04:07:42Z)
• Realization of Trapped Ion Dynamics in the Strong-Field Regime and Non-Markovianity [33.781064984238775]
  We experimentally investigate the dynamics of a trapped ion where the Rabi frequency (Omega) approaches the vibrational mode frequency (nu)<n>Using quantum state tomography, we reconstruct the density matrix and track its evolution to assess non-Markovianity.<n>Our findings establish a pathway for using trapped-ion platforms to investigate non-Markovianity, coherent control, and the fundamental behavior of open quantum systems in extreme regimes.
  arXiv  Detail & Related papers  (2025-10-23T11:25:09Z)
• Probing emergent prethermal dynamics and resonant melting on a programmable quantum simulator [28.28351393962583]
  dynamics of isolated quantum systems following a sudden quench plays a central role in many areas of material science, high-energy physics, and quantum chemistry.<n>Here, we use a programmable neutral atom quantum simulator to explore quench dynamics in spin models with up to 180 qubits.<n>We trace their robustness to Floquet-like prethermal steady states that are stabilized over long emergent timescales.
  arXiv  Detail & Related papers  (2025-10-13T17:58:04Z)
• Observation of non-Hermitian topology in cold Rydberg quantum gases [42.41909362660157]
  We experimentally demonstrate non-Hermitian spectra topology in a dissipative Rydberg atomic gas.<n>By increasing the interaction strength, the system evolves from Hermitian to non-Hermitian regime.<n>This work establishes cold Rydberg gases as a versatile platform for exploring the rich interplay between non-Hermitian topology, strong interactions, and dissipative quantum dynamics.
  arXiv  Detail & Related papers  (2025-09-30T13:44:43Z)
• Constructive interference at the edge of quantum ergodic dynamics [116.94795372054381]
  We characterize ergodic dynamics using the second-order out-of-time-order correlators, OTOC$(2)$.<n>In contrast to dynamics without time reversal, OTOC$(2)$ are observed to remain sensitive to the underlying dynamics at long time scales.
  arXiv  Detail & Related papers  (2025-06-11T21:29:23Z)
• Complexity transitions in chaotic quantum systems: Nonstabilizerness, entanglement, and fractal dimension in SYK and random matrix models [16.646029651172658]
  We study the transition from chaotic to integrable phases in several paradigmatic models.<n>We compare three complementary complexity markers -- fractal dimension, von Neumann entanglement entropy, and stabilizer R'enyi entropy.
  arXiv  Detail & Related papers  (2025-05-14T18:07:18Z)
• Diagnosing Quantum Many-body Chaos in Non-Hermitian Quantum Spin Chain via Krylov Complexity [10.451635171062017]
  We study the emergence of nonchaotic dynamics in a quantum spin chain with a local non-Hermitian disorder.<n>As the disorder strength increases, the emergence of nonchaotic dynamics is qualitatively captured through the growth of Krylov complexity.
  arXiv  Detail & Related papers  (2025-01-27T12:09:49Z)
• Dynamical transition of quantum scrambling in a non-Hermitian Floquet synthetic system [0.0]
  We investigate quantum scrambling in a non-Hermitian quantum kicked rotor subjected to quasi-periodical modulation in kicking potential. We find the dynamical transition from the freezing phase to the chaotic scrambling phase, which is assisted by increasing the real part of the kicking potential. The underlying mechanism is uncovered by the extension of the Floquet theory.
  arXiv  Detail & Related papers  (2024-01-19T23:22:46Z)
• Exceptional entanglement phenomena: non-Hermiticity meeting non-classicality [11.121410238719466]
  Non-Hermitian (NH) extension of quantum-mechanical Hamiltonians represents one of the most significant advancements in physics. Here, we unveil distinct exceptional entanglement phenomena, exemplified by an entanglement transition, occurring at the exceptional point of NH interacting quantum systems. Our results lay the foundation for studies of genuinely quantum-mechanical NH physics, signified by exceptional-point-enabled entanglement behaviors.
  arXiv  Detail & Related papers  (2022-10-10T08:48:18Z)
• Decimation technique for open quantum systems: a case study with driven-dissipative bosonic chains [62.997667081978825]
  Unavoidable coupling of quantum systems to external degrees of freedom leads to dissipative (non-unitary) dynamics. We introduce a method to deal with these systems based on the calculation of (dissipative) lattice Green's function. We illustrate the power of this method with several examples of driven-dissipative bosonic chains of increasing complexity.
  arXiv  Detail & Related papers  (2022-02-15T19:00:09Z)
• Peratic Phase Transition by Bulk-to-Surface Response [26.49714398456829]
  We show a duality between many-body dynamics and static Hamiltonian ground states for both classical and quantum systems. Our prediction of peratic phase transition has direct consequences in quantum simulation platforms such as Rydberg atoms and superconducting qubits.
  arXiv  Detail & Related papers  (2021-09-27T18:00:01Z)
• Dissipative dynamics at first-order quantum transitions [0.0]
  This issue is studied within the paradigmatic one-dimensional quantum Ising model. We analyze the out-of-equilibrium dynamics arising from quenches of the Hamiltonian parameters. We observe a regime where the system develops a nontrivial dynamic scaling behavior.
  arXiv  Detail & Related papers  (2020-09-23T14:08:21Z)
• Driven-dissipative phase transition in a Kerr oscillator: From semiclassical $\mathcal{PT}$ symmetry to quantum fluctuations [0.0]
  We study a minimal model that has a driven-dissipative quantum phase transition. We analyze the critical phenomena in this system, showing which aspects can be captured by each approach. Due to its simplicity and solvability, this model can serve as a paradigm for exploration of open quantum many-body physics.
  arXiv  Detail & Related papers  (2020-07-02T22:39:35Z)

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.