We investigate the impact of a local random unitary noise on multipartite quantum states of arbitrary dimension. We follow the dynamical approach, in which the single-particle unitaries are generated by local random Hamiltonians. Assuming short evolution time we derive an upper bound on the fidelity between an initial and the final state transformed by this type of noise. This result is based on averaging the Tamm-Mandelstam bound and holds for a wide class of distributions of random Hamiltonians fulfilling specific symmetry conditions. It is showed that the sensitivity of a given pure quantum state to the discussed type of noise depends only on the properties of a single-particle and bipartite reduced states.
01254nas a2200193 4500000000100000000000100001008004100002100002200043700002400065700002200089700001900111700001700130700002200147245009300169856004700262300001100309490000700320520073300327 2018 d 1 aMarcin Markiewicz 1 aAdrian Kolodziejski 1 aZbigniew Puchała 1 aAdam Rutkowski 1 aTomasz Tylec 1 aWieslaw Laskowski 00 aUnified approach to geometric and positive-map-based non-linear entanglement identifiers uhttps://doi.org/10.1103/PhysRevA.97.042339 a042339 0 v97 3 aDetecting quantumness of correlations (especially entanglement) is a very hard task even in the simplest case, i.e., two-partite quantum systems. Here we provide an analysis of whether there exists a relation between two of the most popular types of entanglement identifiers: the first one based on positive maps and not directly applicable in the laboratory and the second one a geometric entanglement identifier which is based on specific Hermiticity-preserving maps. We show a profound relation between those two types of entanglement criteria. Hereunder we have proposed a general framework of nonlinear functional entanglement identifiers which allows us to construct experimentally friendly entanglement criteria.
00282nas a2200121 4500000000100000000000100001008004100002260001200043100002000055700002200075245005600097490000700153 2025 d c11/2025 1 aPaweł Błasiak 1 aMarcin Markiewicz 00 aIdentical particles as a genuine non-local resource 0 v11 00332nas a2200133 4500000000100000000000100001008004100002260001200043100001700055700002200072700002000094245007700114490000700191 2024 d c07/2024 1 aJay Lawrence 1 aMarcin Markiewicz 1 aMarek Żukowski 00 aComment on Aurélien Drezet’s Defense of Relational Quantum Mechanics. 0 v54 00299nas a2200109 4500000000100000000000100001008004100002260001200043100002000055700002200075245009200097 d c09/2024 1 aMarek Żukowski 1 aMarcin Markiewicz 00 aAgainst (unitary) interpretation (of quantum mechanics): removing the metaphysical load 00694nas a2200145 4500000000100000000000100001008004100002100002200043700001900065700002200084245007100106856005500177520030200232022001400534 2026 d 1 aMarcin Markiewicz 1 aŁukasz Pawela 1 aZbigniew Puchała 00 aSingle-shot comparison of random quantum channels and measurements uhttps://www.nature.com/articles/s41598-026-70695-z 3 aIn this work we provide an efficiency analysis of the problem of discrimination of two randomly chosen unknown quantum operations in the single-shot regime. We provide tight bounds for the success probability of such a protocol for arbitrary quantum channels and generalized measurements.
a2045-2322 00921nas a2200109 4500000000100000000000100001008004100002100002200043700002400065245005500089520066700144 d 1 aMarcin Markiewicz 1 aKonrad Schlichtholz 00 aUnitary operator bases as universal averaging sets 3 aWe provide a generalization of the idea of unitary designs to cover finite averaging over much more general operations on quantum states. Namely, we construct finite averaging sets for averaging quantum states over arbitrary reductive Lie groups, on condition that the averaging is performed uniformly over the compact component of the group. Our construction comprises probabilistic mixtures of unitary 1-designs on specific operator subspaces. Provided construction is very general, competitive in the size of the averaging set when compared to other known constructions, and can be efficiently implemented in the quantum circuit model of computation.
02162nas a2200145 4500000000100000000000100001008004100002260001200043100001700055700002200072700002000094245007800114490000700192520181700199 2025 d c03/2025 1 aJay Lawrence 1 aMarcin Markiewicz 1 aMarek Żukowski 00 aRelational quantum mechanics is still incompatible with quantum mechanics 0 v15 3 aWe showed in a recent article (Lawrence et al. 2023. Quantum, 7, 1015), that relative facts (outcomes), a central concept in Relational Quantum Mechanics, are inconsistent with Quantum Mechanics. We proved this by constructing a Wigner-Friend type sequential measurement scenario on a Greenberger-Horne-Zeilinger (GHZ) state of three qubits, and making the following assumption: “if an interpretation of quantum theory introduces some conceptualization of outcomes of a measurement, then probabilities of these outcomes must follow the quantum predictions as given by the Born rule.” Our work has been criticized by Cavalcanti et al. (2023. European Journal for Philosophy of Science, 13(4),55). In this note we show that their critique, based on their own reformulation of our argument, does not apply to our paper. It also raises questions of principle which are not answered within the framework of Relational Quantum Mechanics.
01652nas a2200157 4500000000100000008004100001260001500042100002600057700001900083700002200102700002200124245007000146856003700216300000700253520123400260 2026 d c05/29/2026 1 aLudmiła Marcinkowska 1 aŁukasz Pawela 1 aMarcin Markiewicz 1 aZbigniew Puchała 00 aAsymptotic distinguishability of Haar-averaged measurement models uhttps://arxiv.org/abs/2605.31168 a49 3 aWe study discrimination problems generated by the same basic Haar-random measurement mechanism at two observational levels. First, we derive an explicit expression for the type-II error in the task of discriminating a Haar-random measure-and-prepare channel from the identity channel I, using a coherence-sensitive entangled tester. Second, after passing to the induced classical measurement records, we compare two random measurement models: one induced by a single collective unitary of the form U^⊗(n₁+n₂) with U ∈ U(d), and another induced by independent local unitaries U₁^⊗n₁ ⊗ U₂^⊗n₂. For the associated Haar-averaged aggregate histogram laws, in which the block of origin of each count is not retained, we obtain closed-form formulas and quantify their discrepancy through the total variation distance. We derive asymptotic expressions in the fixed-N, large-d regime, the fixed-d, large-N regime, the sparse joint-scaling regime N = o(√d), and the critical scaling regime N/√d → c. We also identify the block-resolved pair-of-histograms law, showing that the aggregate total variation distance is a coarse-grained lower bound on the distinguishability available when block labels are retained. 02013nas a2200157 4500000000100000008004100001260001500042100002200057700001900079700002200098245009800120856003700218300000700255520155200262022004101814 2026 d c25/02/2026 1 aMarcin Markiewicz 1 aŁukasz Pawela 1 aZbigniew Puchała 00 aChoi-level twirling of quantum channels: finite constructions and non-compact transformations uhttps://arxiv.org/abs/2512.23586 a15 3 aTwirling, i.e. averaging over symmetry actions, is a standard tool for reducing quantum states and channels to a symmetry-invariant form. We study channel twirling from the perspective of the channel–state duality and provide a constructive Choi-level description of the averaging map induced by arbitrary input/output representations. Our main technical result concerns the collective setting: for π in(U) = U ⊗tin and π out(U) = U ⊗tout , we introduce a partial-transpose reduction that removes the contragredient action and converts the mixed (walled Brauer) channel twirl into an ordinary Schur–Weyl twirl of the partially transposed Choi operator under U ⊗(tin+tout) , enabling explicit permutation-based formulas without constructing walled Brauer idempotents or mixed Schur transforms. Beyond compact symmetries, we extend channel twirling to reductive, generally non-unitary groups via Cartan decomposition and obtain an invariant-sector decomposition of the averaged Choi operator with weights determined solely by the Abelian Cartan component. Finally, we provide two finite realizations of channel averaging: a “dual” implementation as a convex mixture of unitary-1-design channels acting on invariant sectors, and a design-like reconstruction showing that weighted group t-designs induce channel t-designs for t = tin + tout.
a1751-8121 (online), 1751-8113 (druk)