Evidence of Uncollapsed Quantum Amplitudes After Consecutive Measurements

• URL: http://arxiv.org/abs/2603.13974v1
• Date: Sat, 14 Mar 2026 15:04:39 GMT
• Title: Evidence of Uncollapsed Quantum Amplitudes After Consecutive Measurements
• Abstract summary: Two of the most common interpretations of quantum measurement disagree about the fate of quantum amplitudes after measurement.<n>We experimentally show that these two theories make different predictions when three or more consecutive measurements are performed on the same quantum system.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Two of the most common interpretations of quantum measurement disagree about the fate of quantum amplitudes after measurement, yet this disagreement has not previously led to experimentally distinguishable predictions. In the standard collapse picture, commonly linked to the Copenhagen interpretation of quantum mechanics, measurements eliminate unrealized amplitudes without leaving a memory. In contrast, in the unitary theory, the measurement device registers one of the possible outcomes while remaining part of an entangled state that continues to harbor the unrealized amplitudes. This persistence arises naturally under unitary evolution, since a measurement device that is part of an entangled system cannot serve as a faithful probe of the joint quantum state. Using single-photon measurements of a tunable quantum state, we experimentally show that these two theories make different predictions when three or more consecutive measurements are performed on the same quantum system. Analysis of the joint density matrix of the three measurements reveals coherence among them and supports the unitary theory of quantum measurement. When decoherence is explicitly introduced, the joint density matrix of the quantum system of interest and the apparatus becomes consistent with what a collapse theory would predict. This work clarifies the dynamics of consecutive quantum measurements and offers new insights into the interpretation of quantum measurements.

Related papers

• Time Symmetry, Retrocausality, and Emergent Collapse: The Tlalpan Interpretation of Quantum Mechanics [51.56484100374058]
  The Tlalpan Interpretation (QTI) proposes that the wavefunction collapse is not a primitive, axiomatic rule but an emergent phenomenon.<n>The novelty of QTI lies in its embedding of collapse within the conceptual language of critical phenomena in statistical physics.
  arXiv  Detail & Related papers  (2025-08-25T20:30:56Z)
• Detecting entanglement in any measurement using quantum networks [0.0]
  Entanglement in quantum states is one of the most well-explored areas in quantum physics.<n>We classify composite quantum measurements into two classes: entangled and separable measurements.<n>We show that any rank-one projective entangled quantum measurement gives a quantum advantage.
  arXiv  Detail & Related papers  (2025-02-10T19:26:02Z)
• 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)
• A Quantum Theory with Non-Collapsing Measurements [0.0]
  "Passive quantum theory" is shown to reproduce preparational uncertainty relations, the no-cloning theorem, and no-signalling.<n>The possibility to "observe" a state increases the computational power of some quantum algorithms.
  arXiv  Detail & Related papers  (2023-03-23T16:32:29Z)
• Evolution of many-body systems under ancilla quantum measurements [58.720142291102135]
  We study the concept of implementing quantum measurements by coupling a many-body lattice system to an ancillary degree of freedom. We find evidence of a disentangling-entangling measurement-induced transition as was previously observed in more abstract models.
  arXiv  Detail & Related papers  (2023-03-13T13:06:40Z)
• 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)
• Multiple measurements on an uncollapsed entangled two-photon state [0.0]
  I derive conditions, under which two measurements can be taken on the uncollapsed photon-pair state. The measurements taken by both detectors in this situation are uncorrelated. If experimental results of the proposed experiment disagree with the predictions -- results measured on the quantum state are correlated, new space-time distribution of the quantum state's collapse has to be proposed.
  arXiv  Detail & Related papers  (2022-10-12T09:34:48Z)
• Events in quantum mechanics are maximally non-absolute [0.9176056742068814]
  We prove that quantum correlations can be maximally non-absolute according to both quantifiers. We show that chained Bell inequalities (and relaxations thereof) are also valid constraints for Wigner's experiment.
  arXiv  Detail & Related papers  (2021-12-19T21:15:16Z)
• 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)
• Entanglement and the measurement problem [0.0]
  The "measurement state" (MS) seems to display paradoxical properties such as multiple macroscopic outcomes. Analysis of interferometry experiments using entangled photon pairs shows that entangled states differ surprisingly from simple superposition states.
  arXiv  Detail & Related papers  (2020-02-25T20:54:03Z)

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.