Unraveling-Dependent Metastability in Monitored Quantum Systems and Associative Memories

• URL: http://arxiv.org/abs/2609.06056v1
• Date: Sat, 05 Sep 2026 12:26:06 GMT
• Title: Unraveling-Dependent Metastability in Monitored Quantum Systems and Associative Memories
• Abstract summary: Metastability in open quantum systems is usually inferred from spectral separation in the Liouvillian.<n>We show that conditioned realizations of the same unconditional dynamics can bypass, transiently access, or operationally preserve a metastable memory.
• Score: 0.5161531917413708
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Metastability in open quantum systems is usually inferred from spectral separation in the Liouvillian, which governs unconditional, ensemble-averaged dynamics. We show that this diagnosis is incomplete at the level of individual quantum trajectories: conditioned realizations of the same unconditional dynamics can bypass, transiently access, or operationally preserve a metastable memory, depending on the monitored channel and the observed record. We demonstrate these mechanisms in a driven-dissipative nonlinear oscillator realizing a quantum associative memory, by comparing spectra, target fidelities, and phase-space distributions. The non-Hermitian dynamics obtained by post-selecting on the absence of detected events supports metastable retrieval, but with a distinct long-time fate: normalization selects the least-decaying mode of the non-Hermitian spectrum rather than the addressed memory branch. In contrast, stochastic jump trajectories can preserve retrieval over extended times when the post-measurement update remains compatible with the coherent memory structure. Thus trajectory-level metastability is not determined by the averaged generator alone; it requires compatibility between the monitored channel, the measurement record, and the metastable manifold.

Related papers

• Unsupervised learning for the systematic identification of nondispersive wave packets in driven helium [39.146761527401424]
  Nondispersive wave packets in driven helium are long-lived quantum states that follow classical resonant orbits without spreading.<n>In this work, we introduce an unsupervised learning approach to automate the identification of physically relevant states in the driven helium atom.
  arXiv  Detail & Related papers  (2026-05-25T01:14:16Z)
• Causal-Order Identification of Memoryless Sequential Quantum Processes from Restricted Projective Data [45.85698554568285]
  We find necessary and sufficient conditions for deciding when an observed distribution is compatible with a memoryless sequential quantum process in a fixed direction.<n>We then specialize to the two-qubit Pauli setting, where the problem remains non-tomographic but becomes explicitly tractable.
  arXiv  Detail & Related papers  (2026-05-06T07:16:29Z)
• Completely-positive non-signalling non-Markovian dynamics [0.0]
  We define non-Markovian quantum dynamics as evolution in which the current state depends on all past states.<n>Our work provides a rigorous yet transparent description of the quantum state of non-Markovian systems.
  arXiv  Detail & Related papers  (2026-05-04T22:29:15Z)
• Partial Collapse and Ensemble Invariance under Continuous Quantum Measurement [1.5755923640031846]
  In driven-dissipative quantum systems, continuous measurement can extract information without disturbing the physical steady-state ensemble.<n>Our results clarify how information gain and measurement backaction can be dynamically decoupled in open quantum systems.
  arXiv  Detail & Related papers  (2025-12-23T08:46:17Z)
• 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)
• Generalised fractional Rabi problem [35.18016233072556]
  Fractional quantum dynamics provides a natural framework to capture nonlocal temporal behavior and memory effects in quantum systems.<n>In this work, we analyze the physical consequences of fractional-order quantum evolution using a Green's function formulation based on the Caputo fractional derivative.<n>We find that even in the absence of external driving, the static Hamiltonian term induces non-trivial spin dynamics with damping features directly linked to the fractional temporal nonlocality.
  arXiv  Detail & Related papers  (2025-10-09T12:51:57Z)
• Dissipation-Driven Topological Phase Transition in Quantum Open Systems Independent of system Hamiltonian [2.28437033297544]
  We investigate dissipation-driven topological phase transitions in one-dimensional quantum open systems governed by the Lindblad equation with linear dissipation operators.<n>By employing the modular Hamiltonian framework, we rigorously demonstrate that the $rmZ$ topological invariant characterizing steady states in one-dimensional class D systems is exclusively dependent on the dissipation operators.
  arXiv  Detail & Related papers  (2025-08-22T10:16:11Z)
• On the emergence of quantum memory in non-Markovian dynamics [41.94295877935867]
  Non-Markovian dynamics (with memory) is typical in practice, with memory effects being harnessed as a resource for many tasks like quantum error correction and information processing.<n>Yet, the type of memory, classical or quantum, necessary to realize the dynamics of many collision models is not known.<n>In this work, we extend the quantum homogenizer to the non-Markovian regime by introducing intra-ancilla interactions mediated by Fredkin gates, and study the nature of its memory.
  arXiv  Detail & Related papers  (2025-07-29T15:19:26Z)
• Dynamical learning and quantum memory with non-Hermitian many-body systems [37.69303106863453]
  Non-Hermitian (NH) systems provide a fertile platform for quantum technologies.<n>We investigate this relationship using the example of an interacting NH spin system defined on random graphs.<n>We show that the onset of the first exceptional point corresponds to an abrupt change in the system's learning capacity.
  arXiv  Detail & Related papers  (2025-06-09T11:58:40Z)
• Beyond Entanglement: Diagnosing quantum mediator dynamics in gravitationally mediated experiments [0.0]
  Recent proposals suggest that generating entanglement could serve as a direct test.<n>We show that distinguishing these regimes experimentally remains challenging.<n>Our results provide testable signatures for optomechanical and trapped-ion platforms simulating gravitational interactions.
  arXiv  Detail & Related papers  (2025-06-04T13:10:37Z)
• Switching Dynamics of Metastable Open Quantum Systems [0.4473518548010192]
  Quantum systems like qubits and Rydberg atoms exhibit analogous behavior through collective quantum jumps and long-lived Liouvillian modes with a small spectral gap.<n>Here, we elaborate on the connection between switching dynamics and quantum metastability through the lens of the large deviation principles.<n>These results provide new insights into quantum bistability and the relaxation processes of strongly interacting, dissipative quantum systems far away from the thermodynamic limit.
  arXiv  Detail & Related papers  (2025-05-08T13:00:19Z)
• Emergent quantum correlations and collective behavior in non-interacting quantum systems subject to stochastic resetting [0.0]
  We investigate the dynamics of a non-interacting spin system undergoing coherent oscillations in the presence of Rabi resetting. We show that resetting generally induces long-range quantum and classical correlations. In the thermodynamic limit, the spin system can feature collective behavior.
  arXiv  Detail & Related papers  (2022-02-25T12:22:19Z)

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.