Generalized measurement incompatibility
- URL: http://arxiv.org/abs/2605.16151v1
- Date: Fri, 15 May 2026 16:32:34 GMT
- Title: Generalized measurement incompatibility
- Abstract summary: A weaker notion of joint-measurability, called partial joint-measurability, was proposed by Masini et al.<n>We show that, like full joint-measurability, partial joint-measurability can be decided by solving a single program.<n>Our results highlight the importance of a careful treatment of postselection in security analyses.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Quantum measurements can be incompatible, i.e., they can fail to be jointly measurable. Recently, a weaker notion of joint-measurability, called partial joint-measurability, was proposed by Masini et al. in [Quantum 8, 1574 (2024)]. In this work, we further generalize this notion to the setting where only a subset of the outcomes of each measurement is required to be jointly determined by classical variables. We provide two mathematical formulations of partial joint-measurability and show that, like full joint-measurability, it can be decided by solving a single semidefinite program. We prove that in the case of an untrusted measurement device, an adversary Eve, limited to classical side information, can perfectly guess the outcomes of the measurement device if and only if the set of measurements is partially jointly measurable. We derive analytical thresholds on the detection efficiency below which generic measurements become partially jointly measurable. Such bounds directly yield limits on the robustness of device-independent and semi-device-independent quantum cryptographic protocols against detection inefficiency. In particular, our results highlight the importance of a careful treatment of postselection in security analyses.
Related papers
- Witness robustness: An operational quantifier of measurement resources via free state discrimination [43.748379918040854]
We introduce the witness robustness of a resource quantifier whose measurements consist of free-state witnesses rather than physical measurements.<n>We identify conditions under which faithfulness is recovered and show that, in resource theories admitting a resource-destroying map, the witness vanishes for every measurement.<n>We derive analytical results for projective measurements in single-qubit magic and for binary pure-state projective measurements in the two-qubit entanglement theory.
arXiv Detail & Related papers (2026-07-30T09:08:55Z) - The statistical disturbance bound of quantum measurements [0.0]
Quantifying the disturbance caused by a quantum measurement typically requires detailed knowledge of the underlying measurement channel.<n>We introduce a statistical disturbance bound, which connects the statistical properties of a quantum measurement to the state disturbance induced by any compatible channel.<n>We also develop the weighted state exclusion technique, which enables an experimental determination of the statistical disturbance bound without requiring explicit knowledge of the measurement effects.
arXiv Detail & Related papers (2026-07-17T11:41:22Z) - Quantifying randomness with measurement incompatibility [0.0]
We present a trade-off between the amount of observed measurement incompatibility and the capabilities of a classical Eavesdropper.<n>We find a tight connection between steerability and randomness generation in a setting using any finite number of measurement inputs.
arXiv Detail & Related papers (2026-07-09T16:54:26Z) - All incompatible sets of measurements can generate Buscemi nonlocality [0.0]
The presence of Bell-nonlocality in the correlations arising from measuring spatially-separated systems guarantees that the sets of measurements used are necessarily incompatible.<n>Not all sets of incompatible measurements can however lead to Bell-nonlocality, as there exist incompatible sets of measurements which can only produce local correlations.<n>We prove that all sets of incompatible measurements are nevertheless able to generate nonlocality in an extended Bell scenario where quantum, instead of classical, measurement inputs are considered.
arXiv Detail & Related papers (2025-08-20T04:38:08Z) - Classification of joint quantum measurements based on entanglement cost of localization [42.72938925647165]
We propose a systematic classification of joint measurements based on entanglement cost.
We show how to numerically explore higher levels and construct generalizations to higher dimensions and multipartite settings.
arXiv Detail & Related papers (2024-08-01T18:00:01Z) - Measurement-Device-Independent Detection of Beyond-Quantum State [53.64687146666141]
We propose a measurement-device-independent (MDI) test for beyond-quantum state detection.
We discuss the importance of tomographic completeness of the input sets to the detection.
arXiv Detail & Related papers (2023-12-11T06:40:13Z) - A universal scheme to self-test any quantum state and extremal measurement [41.94295877935867]
quantum network considered in this work is the simple star network, which is implementable using current technologies.
For our purposes, we also construct a scheme that can be used to self-test the two-dimensional tomographically complete set of measurements with an arbitrary number of parties.
arXiv Detail & Related papers (2023-12-07T16:20:28Z) - 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) - Measurement incompatibility is strictly stronger than disturbance [44.99833362998488]
Heisenberg argued that measurements irreversibly alter the state of the system on which they are acting, causing an irreducible disturbance on subsequent measurements.
This article shows that measurement incompatibility is indeed a sufficient condition for irreversibility of measurement disturbance.
However, we exhibit a toy theory, termed the minimal classical theory (MCT), that is a counterexample for the converse implication.
arXiv Detail & Related papers (2023-05-26T13:47:00Z) - Distributed quantum incompatibility [0.0]
We show that the incompatibility which is gained via additional measurements is upper and lower bounded by certain functions of the incompatibility of subsets of the available measurements.
We discuss the consequences of our results for the nonlocality that can be gained by enlarging the number of measurements in a Bell experiment.
arXiv Detail & Related papers (2023-01-20T16:47:18Z) - Measurement incompatibility and quantum advantage in communication [0.0]
Measurement incompatibility stipulates the existence of quantum measurements that cannot be carried out simultaneously on single systems.
We show that the set of input-output probabilities obtained from d-dimensional classical systems assisted with shared randomness is the same as the set obtained from d-dimensional quantum strategies restricted to compatible measurements with shared randomness in any communication scenario.
arXiv Detail & Related papers (2022-09-29T06:45:01Z) - Experimentally determining the incompatibility of two qubit measurements [55.41644538483948]
We describe and realize an experimental procedure for assessing the incompatibility of two qubit measurements.
We demonstrate this fact in an optical setup, where the qubit states are encoded into the photons' polarization degrees of freedom.
arXiv Detail & Related papers (2021-12-15T19:01:44Z) - Device-independent quantification of measurement incompatibility [0.0]
Incompatible measurements are necessary to observe nonlocal correlations.
We provide the direct link between Bell nonlocality and the quantification of measurement incompatibility.
arXiv Detail & Related papers (2020-10-16T15:47:20Z)
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.