Purely quantum memory in closed systems observed via imperfect measurements

• URL: http://arxiv.org/abs/2506.13689v1
• Date: Mon, 16 Jun 2025 16:52:26 GMT
• Title: Purely quantum memory in closed systems observed via imperfect measurements
• Authors: Jorge Tabanera-Bravo, Aljaž Godec,
• Abstract summary: memory in quantum systems is a central problem in the theory of open quantum systems.<n>Little is known, however, about memory effects induced by imperfect measurements on closed systems.<n>We investigate the emergence and characteristics of memory in closed systems observed via imperfect stroboscopic quantum measurements.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The detection and quantification of non-Markovianity, a.k.a. memory, in quantum systems is a central problem in the theory of open quantum systems. There memory is as a result of the interaction between the system and its environment. Little is known, however, about memory effects induced by imperfect measurements on closed systems, where an entanglement with the environment is not possible. We investigate the emergence and characteristics of memory in closed systems observed via imperfect stroboscopic quantum measurements yielding coarse-grained outcomes. We consider ideal and two kinds of imperfect measurements: von Neumann measurements--the analogue of classical lumping--which destroy any coherence in the system, and genuinely quantum-lumping L\"uders measurements preserving certain quantum correlations. Whereas the conditions for Markov dynamics under von Neumann lumping are the same as for classical dynamics, quantum-lumping requires stronger conditions, i.e. the absence of any detectable coherence. We introduce the concept of purely quantum memory having no classical counterpart. We illustrate our results with a quantum walk on a lattice and discuss their implications for dissipative dynamics and decoherence effects induced by more realistic measurements.

Related papers

• 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)
• Entropic witness for quantum memory in open system dynamics [0.0]
  We present a tractable criterion for quantum memory based on the von Neumann entropy.<n>We demonstrate that this criterion is also suitable for detecting quantum memory in continuous-dimensional systems.
  arXiv  Detail & Related papers  (2025-01-29T13:47:16Z)
• Effect of the readout efficiency of quantum measurement on the system entanglement [44.99833362998488]
  We quantify the entanglement for a particle on a 1d quantum random walk under inefficient monitoring. We find that the system's maximal mean entanglement at the measurement-induced quantum-to-classical crossover is in different ways by the measurement strength and inefficiency.
  arXiv  Detail & Related papers  (2024-02-29T18:10:05Z)
• Enhanced Entanglement in the Measurement-Altered Quantum Ising Chain [43.80709028066351]
  Local quantum measurements do not simply disentangle degrees of freedom, but may actually strengthen the entanglement in the system.<n>This paper explores how a finite density of local measurement modifies a given state's entanglement structure.
  arXiv  Detail & Related papers  (2023-10-04T09:51:00Z)
• Quantifying measurement-induced quantum-to-classical crossover using an open-system entanglement measure [49.1574468325115]
  We study the entanglement of a single particle under continuous measurements. We find that the entanglement at intermediate time scales shows the same qualitative behavior as a function of the measurement strength.
  arXiv  Detail & Related papers  (2023-04-06T09:45:11Z)
• Coalescence of non-Markovian dissipation, quantum Zeno effect and non-Hermitian physics, in a simple realistic quantum system [0.0]
  We develop a theoretical framework in terms of the time-dependent Schrodinger equation of motion. The link between the peaked structure of the effective decay rate of the qubit that interacts indirectly with the environment, and the onset of the quantum Zeno effect is discussed in great detail. Our treatment and results have revealed an intricate interplay between non-Markovian dynamics, quantum Zeno effect and non-Hermitian physics.
  arXiv  Detail & Related papers  (2022-06-28T09:28:02Z)
• Quantum spin-flavour memory of ultrahigh-energy neutrino [0.0]
  We study uncertainties related to the interstellar ultrahigh-energy neutrino. We introduce a novel concept: quantum spin-flavour memory. We find that while most measures of quantum correlations show their irrelevance, the quantum spin-flavour is the quantifier of the quantum spin-flavour memory.
  arXiv  Detail & Related papers  (2022-02-07T19:54:05Z)
• Characterization of the measurement uncertainty dynamics in an open system [6.417948558033516]
  Information entropy can perfectly describe this type of randomness in information theory, because entropy can measure the degree of chaos in a given quantum system. In this paper, we investigate the dynamical features of the von Neumann entropic uncertainty in the presence of quantum memory. We put forward some effective operation strategies to reduce the magnitude of the measurement uncertainty under the open systems.
  arXiv  Detail & Related papers  (2021-10-22T15:07:08Z)
• Quantum Causal Inference in the Presence of Hidden Common Causes: an Entropic Approach [34.77250498401055]
  We put forth a new theoretical framework for merging quantum information science and causal inference by exploiting entropic principles. We apply our proposed framework to an experimentally relevant scenario of identifying message senders on quantum noisy links. This approach can lay the foundations of identifying originators of malicious activity on future multi-node quantum networks.
  arXiv  Detail & Related papers  (2021-04-24T22:45:50Z)
• Sensing quantum chaos through the non-unitary geometric phase [62.997667081978825]
  We propose a decoherent mechanism for sensing quantum chaos. The chaotic nature of a many-body quantum system is sensed by studying the implications that the system produces in the long-time dynamics of a probe coupled to it.
  arXiv  Detail & Related papers  (2021-04-13T17:24:08Z)
• Entropic Uncertainty Relations and the Quantum-to-Classical transition [77.34726150561087]
  We aim to shed some light on the quantum-to-classical transition as seen through the analysis of uncertainty relations. We employ entropic uncertainty relations to show that it is only by the inclusion of imprecision in our model of macroscopic measurements that we can prepare a system with two simultaneously well-defined quantities.
  arXiv  Detail & Related papers  (2020-03-04T14:01:17Z)
• An optimal measurement strategy to beat the quantum uncertainty in correlated system [0.6091702876917281]
  Uncertainty principle undermines the precise measurement of incompatible observables. Entanglement, another unique feature of quantum physics, was found may help to reduce the quantum uncertainty.
  arXiv  Detail & Related papers  (2020-02-23T05:27:36Z)

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.