Quantum simulacra

• URL: http://arxiv.org/abs/2607.24739v1
• Date: Mon, 27 Jul 2026 17:59:03 GMT
• Title: Quantum simulacra
• Abstract summary: Quantum simulacra emerge from treating a Hermitian or non-Hermitian quantum system in metrics other than the standard $L2$.<n>Changing the metric redefines the set of system observables and thus the experimental arrangement for their measurement.<n>Simulacrum comes at the cost of implementing measurements of the metric-redefined observables.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Here we analyze the creation of quantum simulacra: phenomena that emerge from treating a Hermitian or non-Hermitian quantum system in metrics other than the standard $L^{2}$. Changing the metric redefines the set of system observables and thus the experimental arrangement for their measurement, making quantum contextuality and microscopic reality metric-dependent. The simulacra therefore consist, on the one hand, of a resizing of the status of quantum measurement, which has always occupied a central role in quantum mechanics: beyond the connection between quantum and classical dynamics, measurements performed in an appropriate metric can emulate a microscopic reality distinct from that prescribed by the Hamiltonian. On the other hand, simulacra provide a route to implementing quantum operations that lie beyond the reach of the $L^2$ metric. Quantum simulacra offer, as an example, an explanation for the recent observation of the violation of Bell inequalities with unentangled photons [Sci. Adv. \textbf{11}, eadr1794 (2025)]: photons that are separable in $L^2$ metric, become entangled when analyzed within a new metric framework. Simulacrum comes at the cost of implementing measurements of the metric-redefined observables; to address this challenge, we propose a scheme combining positive operator-valued measures with postselected subensembles.

Related papers

• Probing the Physical Reality of Projective Measurements [0.0]
  We test whether the postulate of a measurement acting as an instantaneous projection onto an eigenstate of the measurement apparatus is compatible with physical reality.<n>We also develop a continuous description of a quantum measurement finding that its repeated-measurement statistics drastically differ from the projective case.
  arXiv  Detail & Related papers  (2025-06-25T17:04:55Z)
• Quantum-Enhanced Multi-Parameter Sensing in a Single Mode [0.6553834611557042]
  We demonstrate measurements of small changes in position and momentum where the uncertainties are simultaneously reduced below the standard quantum limit.<n>Our experiment uses grid states to measure small changes in position and momentum and shows a metrological gain of up to 5.1(5)dB over the simultaneous measurement.
  arXiv  Detail & Related papers  (2024-12-06T08:58:19Z)
• Entanglement measurement based on convex hull properties [0.0]
  We will propose a scheme for measuring quantum entanglement, which starts with treating the set of quantum separable states as a convex hull of quantum separable pure states. Although a large amount of data is required in the measurement process, this method is not only applicable to 2-qubit quantum states, but also a entanglement measurement method that can be applied to any dimension and any fragment.
  arXiv  Detail & Related papers  (2024-11-08T08:03:35Z)
• 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)
• Observation of partial and infinite-temperature thermalization induced by repeated measurements on a quantum hardware [62.997667081978825]
  We observe partial and infinite-temperature thermalization on a quantum superconducting processor. We show that the convergence does not tend to a completely mixed (infinite-temperature) state, but to a block-diagonal state in the observable basis.
  arXiv  Detail & Related papers  (2022-11-14T15:18:11Z)
• Probing finite-temperature observables in quantum simulators of spin systems with short-time dynamics [62.997667081978825]
  We show how finite-temperature observables can be obtained with an algorithm motivated from the Jarzynski equality. We show that a finite temperature phase transition in the long-range transverse field Ising model can be characterized in trapped ion quantum simulators.
  arXiv  Detail & Related papers  (2022-06-03T18:00:02Z)
• Simulability of high-dimensional quantum measurements [0.0]
  We demand that the statistics obtained from $mathcalM$ and an arbitrary quantum state $rho$ are recovered exactly by first compressing $rho$ into a lower dimensional space. A full quantum compression is possible, if and only if the set $mathcalM$ is jointly measurable. We analytically construct optimal simulation models for all projective measurements subjected to white noise or losses.
  arXiv  Detail & Related papers  (2022-02-25T21:22:29Z)
• The measurement problem and the completeness of quantum states [0.0]
  We show that equivalence of quantum reduced states and statistical mixed states of ensembles possesses profound physical underpinnings.<n>We give a possible solution to the quantum measurement problem.
  arXiv  Detail & Related papers  (2021-04-07T19:46:14Z)
• Quantum Zeno effect appears in stages [64.41511459132334]
  In the quantum Zeno effect, quantum measurements can block the coherent oscillation of a two level system by freezing its state to one of the measurement eigenstates. We show that the onset of the Zeno regime is marked by a $textitcascade of transitions$ in the system dynamics as the measurement strength is increased.
  arXiv  Detail & Related papers  (2020-03-23T18:17:36Z)
• 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)

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.