Year: 2026
Type: preprint
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.
Source: arXiv (Cornell University)
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1175115578, G1536341141, G1690208154, G1722358650, G2105336002, G2262748287, G2601397997, G2928636548, G300979063, G3480869486, G3681454997, G4042783231, G410571670, G425668148, G451917667, G4579131420, G4692141684, G5080475149, G5195188938, G5271502856, G5539308778, G575169067, QuantERA II ERA-NET Cofund in Quantum Technologies, G5967599077, G6033112984, G61011433, G6181615152, G6552004136, G7084143925, G7169023097, G8575212178, G8638682022
OpenAlex ID: W7212078071