arXiv subjects

Patryk Michalski

Publications and source records attributed to Patryk Michalski.

6 recordsLinked to original sources

arXiv2026

Strongly coupled atom-cavity systems under boundary modulation: simulating gravitational-wave effects

One of the proposed platforms in which both quantum and general relativistic effects can become observable is an atom interacting with the electromagnetic field in a gravitational-wave background. The periodic modulation of field modes induced by variations of the spacetime metric modifies the atomic emission spectrum. Notably, the temporal modulation of the mode-frequency induced by a plane gravitational wave can be simulated through modulated boundary conditions, such as moving cavity mirrors. We analyze the impact of this modulation on atom-field interactions in the strong atom-cavity coupling regime, where Rabi oscillations occur. We show analytically that the modulation is resonantly enhanced, leading to measurable imprints in the atomic transition probability. This establishes a realistic and experimentally accessible platform for probing analogue general relativistic effects in quantum optical systems.

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arXiv2026

Device-independent certification of tripartite quantum networks with bilocal Bell inequalities

While quantum networks have been extensively studied as a natural extension of the standard Bell scenario with a richer correlation structure, general constructions of nonlinear Bell inequalities with self-testing properties are still largely lacking. In this work, we present a general method for constructing such inequalities in the simplest network scenario, in which two independent sources distribute bipartite quantum states to three spatially separated observers. These inequalities allow for arbitrary numbers of binary measurements and are maximally violated by maximally entangled states of the corresponding local dimensions together with sets of pairwise anticommuting Clifford observables. Importantly, their maximal quantum values can be determined analytically, which makes them particularly promising for device-independent applications. In particular, we prove that these Bell inequalities can be used to device-independently certify the underlying quantum network, including both the quantum states produced by the sources and the observables measured by all parties. To the best of our knowledge, this is the first self-testing result for quantum networks that relies solely on the maximal violation of a nonlocality witness.

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arXiv2025

Detection of quantum entanglement across the event horizon

We investigate the problem of distinguishing between separable and entangled states of two quantum wave packets, one of which falls into a black hole. Intuitively, one might expect the two scenarios to be indistinguishable, since the information carried by one wave packet is hidden beyond the event horizon. We show, however, that fundamental limitations on the localizability of quantum states can render the two scenarios, in principle, distinguishable. Employing tools from quantum state discrimination theory, we analyze a concrete realization and discuss the configurations that maximize the probability of successfully distinguishing between the two cases.

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arXiv2025

Systematic construction of ROCN Bell-inequalities

Self-testing constitutes one of the most powerful forms of device certification, enabling a complete and device-independent characterization of a quantum apparatus solely from the observed correlations. In recent work by the authors [23], a general framework was introduced for constructing Bell inequalities that self-test entire families of Clifford generators. In this manuscript, we develop an alternative and complementary self-testing criterion based on symmetric spanning sets. This formulation provides an explicit and constructive route to designing self-testing Bell inequalities in arbitrary dimensions.

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arXiv2025

Certifying Majorana Fermions with Elegant-Like Bell Inequalities and a New Self-Testing Equivalence

Bell inequalities provide a fundamental tool for probing nonlocal correlations, yet their quantum bound, that is, the maximal value attainable through quantum strategies, is rarely accessible analytically. In this work, we introduce a general construction of Bell inequalities for which this bound can be computed exactly. Our framework generalizes both the Clauser-Horne-Shimony-Holt and Gisin's elegant inequalities, yielding Bell expressions maximally violated by any number of pairwise anticommuting Clifford observables together with the corresponding maximally entangled state. Under suitable assumptions, our inequalities also enable the device-independent certification of Majorana fermions, understood as multiqubit realizations of Clifford algebra generators. Importantly, we identify an additional equivalence that must be incorporated into the definition of self-testing beyond invariance under local isometries and transposition. This equivalence arises from partial transposition applied to the shared state and to the measurements, which in specific cases leaves all observed correlations unchanged.

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arXiv2024

Stories in the two-state vector formalism

The two-state vector formalism of quantum mechanics is a time-symmetrized approach to standard quantum theory. In our work, we aim to establish rigorous foundations for the future investigation within this formalism. We introduce the concept of a story - a compatible pair consisting of a two-state vector and an ideal measurement. Using this concept, we examine the structure of the space comprising all two-state vectors. We analyze the problem of distinguishability and confirm that some pairs of two-state vectors or their statistical mixtures cannot be physically distinguished. In particular, we discuss an example of a two-state vector that is indistinguishable from a statistical mixture of separable two-state vectors and provide an example of a two-state vector that can be distinguished from every such mixture. This leads us to formulate the definition of a strictly non-separable two-state vector as a genuine manifestation of entanglement between the past and the future.

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