Papers

We consider bipartite exact entanglement embezzlement with a catalyst state vector $\psi$ in a Hilbert space $\mathcal{H}$ using unitaries (or more generally, contractions). If $\mathcal{M} \subseteq \mathcal{B}(\mathcal{H})$ is a von Neumann algebra and $U \in M_d \otimes \mathcal{M}$ and $V \in \mathcal{M}' \otimes M_d$ are unitaries (or more generally contractions), then such a protocol is of the form $(U \otimes I_d)(I_d \otimes V)(e_0 \otimes \psi \otimes e_0)=\sum_{i=0}^{d-1} \alpha_i e_i \otimes \psi \otimes e_i$, where each $\alpha_i>0$ and $\sum_{i=0}^{d-1} \alpha_i^2=1$. We show that any such protocol must arise from a unique state on the tensor product $\mathcal{O}_d \otimes \mathcal{O}_d$ of the Cuntz algebra with itself. As a result, we prove that exact entanglement embezzlement is a self-test for a collection of $d$ Cuntz isometries for each party and a unique quasi-free state on the Cuntz algebra $\mathcal{O}_d$ in the sense of \cite{Iz93}. Moreover, we use modular theory to show that the von Neumann algebra generated by the copy of $\mathcal{O}_d$ is the unique separable approximately finite-dimensional Type $\text{III}_{\lambda}$ factor for some $0<\lambda \leq 1$, where $\lambda$ can be determined by an algebraic condition on the Schmidt coefficients of the state $\varphi=\sum_{i=0}^{d-1} \alpha_i e_i \otimes e_i$.

Local Markovian noise cannot bring entanglement back, but it can bring magic back. Unlike separability, stabilizer membership is not preserved by local channels, allowing dissipation to push states out of the stabilizer polytope as well as in. Under local amplitude damping, the $n$-qubit GHZ family $\alpha|0^n\rangle+\beta|1^n\rangle$ ($0<\alpha<\beta$) loses its magic at a lower damping strength $\gamma_-$ and regains it at a higher one $\gamma_+$, while entanglement is irreversibly lost at $\gamma_e$. This magic–entanglement complementarity, $\gamma_e+\gamma_+=1$ for every $n$, reflects a system–environment duality of amplitude damping. Within real phase-covariant Markovian semigroups the phenomenon is mapped out in full: zero-temperature rebirth occurs if and only if $T_2>T_1$, unital dynamics produce no rebirth, and sufficiently weak thermal excitation confines rebirth to a finite magic island ending in a second sudden death. For small $\alpha$, the reborn magic resides in a fully separable state with all proper marginals stabilizer, yet parity-syndrome extraction concentrates it onto a single qubit for magic-state distillation, without loss of expected robustness and with optimal per-register yield $\alpha^2/2$. Local dissipation further divides pure stabilizer states into magic-generators and magic-insulators: at two qubits, the Bell state $|\Phi^+\rangle$ generates magic immediately, while its Bell-state partner $|\Psi^+\rangle$ remains stabilizer. Together, magic and entanglement reveal a symmetry invisible to either alone.

Measurement-based quantum heat engines have attracted significant interest as alternatives to conventional thermal engines, as they replace the hot thermal reservoir with quantum measurements, thereby offering greater controllability and simpler implementation. Motivated by these advantages, we investigate a measurement-driven quantum Otto engine with a qubit working substance and study the optimal work extractable from such engines, including whether their performance can surpass that of conventional quantum Otto cycles. We analyze the engine in both the infinite-time (adiabatic) and finite-time (non-adiabatic) regimes, considering two distinct implementations obtained through optimization over all projection-valued measurements (PVMs) and over all two-outcome positive operator-valued measurements (POVMs). We show that measurement-based engines can outperform conventional quantum Otto engines within specific parameter regimes and that POVM-based engines can yield higher optimal work extraction than PVM-based ones. Furthermore, by incorporating the thermodynamic cost associated with resetting the auxiliary system required for POVM implementation, we demonstrate that the resulting net work output can still exceed that of PVM-based engines under suitable conditions on the spectral gaps and cold bath temperature. We also identify regimes in which non-adiabatic implementations can yield higher work output and efficiency than their adiabatic counterparts. Our study provides operational guidelines for designing improved measurement-driven quantum Otto engines.

We investigate the solid-state implementation of a Dicke-like quantum battery consisting of a two-dimensional material-based Josephson junction inductively coupled to a resonator, using graphene as a representative example. In this configuration, Andreev bound states naturally act as non-interacting, energetically non-degenerate two-level systems, and the setup allows for both single-photon and two-photon resonant processes. The coupling between the LC-circuit flux and the supercurrent through the junction gives rise to peculiar longitudinal interaction terms that have no counterpart in the conventional Dicke model. These additional couplings can enhance energy storage for a proper range of parameters. The proposed architecture also enables an alternative, but equivalent, charging protocol that relies on tuning the superconducting phase difference across the junction.

We demonstrate a practical countermeasure against a well-known class of attacks on quantum key distribution (QKD) systems that exploit detection efficiency mismatch, where the receiver's detectors do not exhibit identical responses to incoming photons across all degrees of freedom. This class of quantum hacking strategies is broad and significantly includes the time-shift attack, which targets an arrival-time-dependent side channel at the receiver. The four-state countermeasure, previously only proven to be secure in theory, is implemented here on a GHz-clocked prototype QKD system and evaluated for its security and performance. We show that its presence enables almost complete recovery of the system's ideal secret key rate. Our results provide strong justification for adopting this countermeasure as a standard component in future scalable and practical QKD systems.

An adversary copies your encrypted traffic today and waits for a quantum computer to decrypt it later. How exposed are you? We show that the functional form of the answer is not merely a calibration choice – it is structurally justified by three assumptions about adversarial production and value-decay dynamics. Under those assumptions, the HNDL compromise probability factorises into a temporal hazard, a multiplicative cryptographic-vulnerability and operational-exposure term, and a saturation denominator governed by the defense-attack intensity ratio; the marginal sensitivity to each dimension is endogenous to the organisation's position in the vulnerability-exposure plane, not a fixed global constant. Additive scoring frameworks cannot reproduce this structure because the interaction between cryptographic vulnerability and operational exposure is absent by construction, regardless of calibration. The resulting framework provides a structurally grounded basis for operational HNDL exposure prioritisation under partial observability.

We compute the entanglement dynamics across a monitored quantum point contact, where particle losses are recorded on a given site, and demonstrate how this single-site local monitoring substantially reshapes the entanglement production. Contrary to the unitary case, where entanglement entropy grows logarithmically in time, here we find first a linear growth, up to a maximum value displaying volume-law scaling, and then a slow decay to zero, as the system empties out. We capture this crossover using a quasiparticle picture, where the first linear growth arises due to an emergent bias voltage established by the losses, which eventually decays away as the system depletes. We connect our results to studies of the Page curve and to experimentally relevant probes, via full counting statistics of charge transfer across a subregion, with only a single channel to unravel leading to a favorable scaling of the postselection overhead. Natural platforms for this setting include mesoscopic systems and ultracold atoms.

We investigated the possibility that a single measurement run with a definite outcome is a joint unitary evolution of all the participating systems, and measurement runs with different definite outcomes correspond to different unitary maps. With reasonable assumptions, we derived a lower bound of the dependence of the environment after measurement on the state of the system before measurement, conditioned on the same measurement outcome. An experimental test of this dependence relation can either serve as evidence that the unitary dynamics and the definite outcome in the orthodox sense cannot be true together or suggest a deviation from the von Neumann measurement model plus a "conditioning" interpretational step.

Scalable trapped-ion quantum computing is commonly realized with modular chips that feature distinct zones with specific functionalities, such as storage, state preparation, and gate execution. To execute a quantum circuit, the ions must be transported between these zones. This process is called ion shuttling. To achieve reliable computation results, the shuttling process must be optimized. However, as the number of ions increases, this becomes a high-dimensional optimization problem where optimal solutions cannot be computed efficiently. We demonstrate, to the best of our knowledge, the first use of reinforcement learning (RL) for the optimization of ion shuttling. RL is well-suited for such scenarios, as it enables learning a strategy through direct interaction with the problem. We show that our RL approach outperforms current state-of-the-art heuristic techniques, yielding a reduction in shuttling operations of up to 36.3 %. Furthermore, we show that our method is easily applicable to various chip architectures. Our approach offers a versatile method to study shuttling efficiency during chip design and, therefore, a highly relevant tool for future, more complex architectures.

We present a streamlined implementation of a computational framework for constructing and analyzing reduced dynamical maps for complex system–bath models at finite temperature. The methodology is based on three established ingredients of quantum dynamics: the Choi–Jamiołkowski isomorphism for the representation of quantum channels, thermofield (TFD) purification of thermal environments, and tensor-train (TT) propagation of the resulting enlarged pure state. The reduced map is obtained from a single unitary propagation in a thermofield-doubled Hilbert space and represented in matrix form through the Choi–Jamiołkowski isomorphism. The TFD evolution is implemented in the TT representation, enabling efficient propagation of high-dimensional purified thermal states. We illustrate the methodology for exciton transfer in the Fenna–Matthews–Olson complex with site-dependent structured spectral densities represented by discretized bosonic environments. The resulting maps are used to analyze decoherence, relaxation, and finite-memory effects, and to assess the crossover to an effectively time-local description. The proposed approach provides a route to compute reduced propagators and to post-process them into memory kernels, transfer tensors, and effective kinetic rate descriptions for complex molecular systems.

We study permutation-invariant quantum codes in the symmetric subspace $\mathrm{Sym}^n(\mathbb{C}^q) $ of $n$ qudits of local dimension $q$. For every integer $q\geq 2$, we construct a permutation-invariant code with parameters $((4,q,2))_q$. Thus four physical qudits suffice to encode one logical qudit with distance two in the symmetric sector for every local dimension. We also show, using linear-programming constraints for permutation-invariant quantum codes, that no permutation-invariant code of dimension $q$ and distance at least $2$ exists in $\mathrm{Sym}^n(\mathbb{C}^q)$ for $n\leq 3$. Hence four qudits are necessary and sufficient. The construction has a simple representation-theoretic and combinatorial description. In the irreducible $\mathrm{SU}(q)$-module $\mathrm{Sym}^4(\mathbb{C}^q)$, the distance-two Knill-Laflamme conditions split into root and Cartan parts. By restricting supports to the even-entry occupation layer, all root-error conditions vanish automatically. The remaining Cartan conditions reduce to linear balancing constraints on packets of occupation vectors. These packets admit a natural graph-theoretic interpretation in terms of the vertices and edges of the complete graph $K_q$: for odd $q$, they are organized by the midpoint rule, while for even $q$, they are organized by a decomposition of $K_q$ into perfect matchings. In this way, the existence of minimal $((4,q,2))_q$ permutation-invariant codes is reduced to a parity-dependent edge-coloring problem on $K_q$.

As trapped-ion quantum computing scales to larger qubit registers and more complex control protocols, classical control systems face a fundamental tradeoff: sub-microsecond board-level feedback requires tight hardware coupling, whereas maintainability and extensibility require clean, modular software abstractions. This paper presents QuCtrl-BELL (Bell), a compiler-driven software stack for trapped-ion quantum control. The design resolves this tradeoff by decoupling control flow – including loops, branches, and synchronization – from hardware state data. A Python-embedded domain-specific language (DSL) is lowered through a six-stage transpilation pipeline covering control flow graph (CFG) construction, static single-assignment (SSA) conversion, liveness analysis, and graph-coloring register allocation. The compiler generates deterministic distributed board-level programs and compact step-table data. A cross-board synchronization protocol supports feedback loops with latency below 700~ns without host intervention. Bell is deployed and evaluated on the QuCtrl-BELL platform (RISC-V + PXIe), demonstrating that a compiler-based infrastructure can provide programmability, deterministic timing, and modularity for scalable trapped-ion quantum control.

We study long-range nonstabilizerness (LRN), namely the obstruction to remove nonstabilizerness with shallow-depth local quantum circuits. In one-dimensional settings, the mutual information between disconnected spatial regions has proven to be a powerful tool to diagnose LRN. In this work, we focus on encoded states of two-dimensional topologically-ordered systems, and explore the ability of the mutual information to serve as a diagnostic of LRN. Focusing on the concrete setting of lattice models defined on a torus, we show that information about LRN can be gained from the analysis of the mutual information between non-overlapping regions containing non-contractible loops, and of the change of such mutual information under modular real-space transformations. We exemplify this idea in the toric code and the non-abelian string-net model with doubled Fibonacci topological order. In the former case, we show that the mutual information provides a full classification, certifying LRN for all encoded non-stabilizer states. In the latter case, instead, our approach does not lead to a full classification, as it detects LRN for all states except from a finite subset with special transformation properties under the modular group. Finally, we discuss how our results on LRN constrain the logical gates that can be implemented fault-tolerantly on the torus.

This work discusses two retrodictions of the ratchet universality (RU) law which explain previous numerical and experimental findings concerning the diode effect in conventional superconducting tunnel-junctions (TJ) and the controlled suppression of electron-hole pair generation in a TJ, both under biharmonic driving fields. We demonstrate that the interplay between the RU law and the Heisenberg's uncertainty principle leads to a universal scenario of optimal quantum transport. Specifically, we demonstrate that the RU driving field maximizes the diode's efficiency while yielding a maximal rectification range for the supercurrent, on the one hand, and optimally reduces the excess quantum noise with respect to the dc noise level, thus allowing for the efficient production of nonclassical photonic states. These results suggest that the RU law seems essential for any optimal application of the ratchet effect, particularly in the contexts of superconducting integrated power electronics, electron quantum optics, and quantum computing.

In most stabilizer-based quantum computing schemes, so-called magic states are a necessary resource for implementing non-transversal quantum gates. With the resource theory of magic, it is possible to analyze and quantify the generation of the non-stabilizer states. The relative entropy is a measure used in various resource theories. For single qubits, we characterize magic states and their closest stabilizer states by applying analytical results known from the relative entropy of entanglement and show that the magic states and their closest stabilizer states are arranged symmetrically around the states at the centers of the faces of the stabilizer octahedron. For tensor products of single-qubit states, we prove analytically that the relative entropy of magic is nonadditive in almost all cases.

Experiments performed on quantum systems often measure multitime correlation functions. When quantum systems are weakly coupled to their environment, the time evolution of such correlation functions can be reduced to that of the reduced density matrix by the quantum regression theorem (QRT). While no QRT is available for general non-Markovian open quantum systems, we show that for time-independent Hamiltonians and finite memory times $\tau_c$, an exact factorization rule exists that relates higher-order multitime correlations to products of lower-order correlations. Consequently, all information needed to reconstruct $n$-time correlations is contained in a temporal volume of $\mathcal{O}(\tau_c^n)$. On the example of quantum dots coupled to phonons, we demonstrate that this factorization makes numerical calculations of multitime correlations extremely efficient and even enables semianalytical solutions in systems where the standard QRT breaks down.

We report the demonstration of a bulk, intrinsically phase-stable source of polarization- and time-energy-entangled photon pairs at 810nm and 1550nm, directly coupled into single-mode optical fibers. This highly non-degenerate wavelength combination is well suited for hybrid quantum communication networks, enabling low-loss transmission in optical fibers at 1550nm while maintaining efficient free-space propagation and detection at 810nm. The source is based on spontaneous parametric down-conversion in a periodically poled lithium niobate crystal embedded in a polarization Sagnac interferometer, providing inherent stability and dual-degree-of-freedom entanglement. We measure a spectral brightness of B = 4800 pair/s/mW/GHz, with fiber coupling efficiencies exceeding 0.48 at both wavelengths. The entanglement quality is characterized by high-visibility two-photon interference, yielding net visibilities of 0.995 in the polarization basis and 0.991 in the energy-time basis. These performances demonstrate a compact and robust entanglement source compatible with hybrid fiber/free-space quantum key distribution architectures, and suitable for future ground-to-satellite quantum communication links.

Forbidden atomic transitions provide some of the most stringent low-energy tests of physics beyond the Standard Model, with sensitivity set by the interplay between the sought-for signals and systematics suppressed by symmetry. Here we identify the previously unobserved $4f^{6}6s^{2}\,{}^{5}$D$_{0}$ level of neutral samarium at $14\,564.90(2)\,\mathrm{cm}^{-1}$, opening the ${}^{7}$F$_{0}\rightarrow{}^{5}$D$_{0}$ inner-shell transition for precision spectroscopy. Candidate lines extracted from dual-comb absorption spectra were assigned using double-resonance population-depletion and sequential-excitation measurements. The observed pressure broadening, $0.12(2)\,\mathrm{MHz/torr}$, and pressure shift, $-0.145(4)\,\mathrm{MHz/torr}$, indicate an inner-shell $4f$-transition shielded from external perturbations. Many-body calculations predict a metastable lifetime in the range $120$-$200\,\mathrm{ms}$, corresponding to a quality factor of order $\mathcal{Q}\sim10^{14}$, large sensitivity coefficients for variation of the fine-structure constant, and a nuclear-spin-dependent parity-violation amplitude comparable to that of cesium. Crucially, the $J=0\rightarrow J=0$ selection rule suppresses by symmetry both the nuclear-spin-independent parity-violation channel and the M1 and E2 backgrounds that complicated previous heavy-atom experiments, yielding a uniquely clean window onto the nuclear anapole moment. The two stable spin-$7/2$ isotopes of samarium provide a remarkable opportunity to largely cancel atomic-structure uncertainties by measuring the ratio of parity-violation effects in the two isotopes. These results establish neutral samarium as a platform for inner-shell precision spectroscopy and tests of physics beyond the Standard Model.

Modular variables serve as a striking example of quantum nonlocality, particularly in superpositions of wave packets that are spatially well separated, where the relative phase between components cannot be accessed through conventional local measurements. In this work, we explore the time evolution of Hermitian modular operators for Gaussian wave-packet superpositions under the influence of a uniform gravitational field. We consider both unitary dynamics governed by the Schrödinger equation and open-system dynamics described by the Caldeira-Leggett master equation in the high-temperature limit. Adopting the Bohmian interpretation of quantum mechanics, we compute local expectation values of these modular operators along individual particle trajectories. Our analysis shows that gravitational acceleration induces a time-varying modular signal, the expectation value of the modular observable, that remains sensitive to the relative phase between the separated wave packets. In contrast, standard local quantities such as the probability density and probability current, while modified by gravity, become insensitive to the relative phase in the regime of negligible spatial overlap. For a pair of particles coupled to a shared environment, we find that environment-induced correlations can modify the local modular expectation value observed for one particle, yielding a clear signature of environmental influence. However, the transfer of phase sensitivity via environment-generated entanglement to the modular signal of the distant particle remains negligible within the regime considered. We further demonstrate that conventional measures of coherence and entanglement do not capture the relative phase information in this non-overlapping regime.

Optically trapped ultracold polar molecules can have multiple long-lived states for coding quantum information, and can exhibit electric dipole-dipole interactions~(DDI) which enables entanglement generation. The general understanding on the quantized motion~(QM) of molecules in the traps is that it causes fluctuation of DDI. Here, we find that the molecular QM can realize an asymmetric quantum Rabi model, which is of specific importance in the study of fundamental physics. The molecular QM can also lead to an exotic trap-dipole resonance, resulting in excess population loss to uncoupled motional states, and, hence, should be avoided in a general quantum control over polar molecules. To examine the impact of QM on quantum computing based on polar molecules, we introduce two gate protocols, a fast iSWAP gate which can be realized by a global microwave pulse of pulse area smaller than $2\pi$, and a controlled-phase gate with an arbitrary controlled phase, and find that both gates can attain a high fidelity.

We emulate optically interconnected quantum processors in ring, star, and line topologies using a quantum computer. GHZ benchmarks show that the star provides the best trade-off between cost and fidelity under transduction and fiber noise.

This work develops a conceptual framework for the foundations of quantum physics, linking two main approaches: the algebraic formulation and quantum probability. Rather than proposing new axioms or theories, the text reorganizes and synthesizes existing models, highlighting their assumptions, conceptual structures, and operational significance. The analysis begins with von Neumann's measurement theory and its subsequent developments by Mackey, emphasizing the role of experimentally feasible procedures and the need for a statistical model grounded in laboratory practice. The work adopts an operational perspective, according to which physical quantities are defined solely through experimental measurement methods, and the corresponding probabilistic measures are derived from measurement outcomes. The introduction critically examines the limitations of purely mathematical formulations - such as the algebraic method - when separated from experimental interpretation. The text argues for a clear distinction between axioms, postulates, and presuppositions, and for a reconstruction of quantum theory that respects both empirical constraints and conceptual clarity. Overall, the goal is to provide a coherent path from operational principles to algebraic structures, offering a basis for an axiomatic reformulation of quantum mechanics that remains faithful to physical practice.

Not all entangled states are useful for quantum teleportation. We present a geometric method to construct optimal teleportation witnesses, which provide operational necessary and sufficient criteria for identifying the teleportation usefulness of arbitrary two-qudit entangled states. Specifically, by developing a two-layer iterative cutting-plane algorithm to solve the shortest distance problem from the target state $\rho$ to the convex set $S$ of useless states, we obtain the projection point $\sigma^* \in S$ and then construct the optimal teleportation witness from the projection geometry. Moreover, the shortest distance $D(\rho)$ obtained during this construction also serves as a necessary and sufficient criterion for usefulness. We apply our method to identify the teleportation usefulness of three classes of entangled states.

I point out three ways in which the perspective of quantum information may lead to distorted claims about physics: forgetting that light does not need to be quantised to show coherence; ignoring the generators of unitary evolutions; and approaching the discovery of nature as a fight against an adversary.

Although numerous measures of entanglement have been proposed so far, the calculation of a given faithful entanglement measure is a hard work since it is always involved in some optimization process. It is, therefore, important to estimate the lower bound of a given entanglement measure for an arbitrary quantum state. This results in a subject of intensive mathematical research. In particular, along this line, the lower bounds of concurrence or other measures that are induced from concurrence have been explored a lot. Here, we investigate the lower bounds of two kinds of entanglement monotones, i.e., $q$-concurrence ($q>1$) and $\alpha$-concurrence ($0<\alpha<1$), or termed the parameterized entanglement monotone together. We obtain, in the light of the informationally complete ($N$, $M$)-positive operator-valued measure [($N$, $M$)-POVM], the lower bounds for the case of $\frac12<\alpha<1$, $1<q<2$ for two-qudit states, and the case of $2\leqslant q<3$ for two-qubit states. We list several examples which show that the lower bounds based on ($N$, $M$)-POVM outperform that of GSIC-POVM and SIC-POVM, and all these measurement based bounds are better then the ones induced by positive partial transpose (PPT) and realignment criteria in literature. In addition, we obtain an analytical formula of the parameterized entanglement monotone with $\frac12<\alpha<1$ and $1<q<2$ for the isotropic state.

Open optical or plasmonic resonators are placed on and connected through surfaces or via waveguides, forming complex lightguiding nanostructures, e.g. for integrated photonic quantum devices. We derive general boundary conditions for quasinormal modes that account for the structure's specific geometry. We then present a general quantization scheme for multiple, interacting quasinormal-mode cavities coupled to quantum emitters and to a non-bosonic bath of propagating photons on waveguides or a surface. We derive a system-bath Hamiltonian with rigorously defined coupling elements that can be computed using Maxwell solvers, including light-matter coupling between the electromagnetic field and quantum emitters. We define system-bath correlation functions for an effective, bath-mediated, and time-delayed interaction between the quasinormal modes and quantum emitters, which is a main ingredient commonly used to simulate open quantum system dynamics.

Controlled interaction of laser light with electron beams is fundamental for ultrafast electron microscopy and electron-based quantum optics, yet their direct coupling is forbidden in free space. Here we use longitudinally polarized light at a thin membrane and show that the emerging focal fields can modulate the electron beam in a direct, coherent and linear way, without the need for nanostructured materials or slanted interaction geometries. Also, we use vectorial polarizations to excite and probe three-dimensional nanophotonic near-fields in metallic mesocrystals by coherent electron energy gain and loss. We find that longitudinal electric fields excite axial near-fields in a direct way while longitudinal magnetic fields excite oscillating ring currents via azimuthal electric fields. These possibilities enable tilt-free, collinear generation of attosecond electron pulses or free-electron qubits and provide novel imaging modes in ultrafast electron microscopy and metamaterial tomography.

The unified entropy as a promotion of the von Neumann entropy exhibits distinct diversity which contains the Tsallis entropy, the Rényi entropy, the von Neumann entropy as special cases. The unified-($r,t$) entropy entanglement with $0<r<1$ and $0< t\leq 1$ was shown to be an entanglement monotone in literature. In this paper, we explore unified-($q,s$) entropy entanglement with $q>1$ and $qs\geq1$ and show that it is also an entanglement monotone and that both of them are monogamous. Going further, we present two kinds of global multipartite entanglement measures (GlMEMs) based on the unified entropy and each kind has two subclasses which are classified by the parameters $(q,s)$ and $(r,t)$. Consequently, from the view of the complete multipartite entanglement measure theory, we show that one of them is a complete multipartite entanglement monotone and is not only completely monogamous but also tightly completely monogamous, but the other three are even not complete. We also explore the genuine entanglement measures induced by the unified entropy and the relations with the bipartite entanglement and the global entanglement are discussed, respectively.

Photonic quantum computing is a promising platform for scalable quantum machine learning, but designing effective hybrid architectures remains challenging under hardware and optimization constraints. Existing approaches rely on manually tuned architectures that fail to account for the collaboration between classical preprocessing, phase encoding, and photonic circuit structure, limiting both accuracy and hardware compatibility. In this paper, we propose a neural architecture search framework for hybrid photonic quantum-classical models that combines genetic algorithm-based search with learnable quantum phase encoding to systematically explore the joint design space of classical and quantum components. Our framework encodes 19 hyperparameters across six gene groups and evolves a population of hybrid architectures using group-based crossover, per-gene mutation, and elitism, evaluating each candidate on a short training budget before full retraining of the best found design. We evaluate our framework on two image classification benchmarks, Digits and MNIST, achieving final validation accuracies of 99.44% and 98.78%, respectively, with first-principles execution time estimates on the Quandela Ascella photonic QPU projecting single-image inference at ~67 ms (Digits) and ~149 ms (MNIST). Our quantum contribution analysis further shows that the photonic layer extracts non-redundant features orthogonal to the classical pathway, providing a measurable accuracy advantage over classical-only baselines. Our results demonstrate that automated architecture search is both practical and impactful for hybrid photonic systems, opening the way for systematic design space exploration of quantum AI on photonic devices.

We establish a correspondence between two independent entropic probes – the variation of Rényi mutual information (RMI) across the electroweak symmetry breaking (EWSB) transition and the stabilizer Rényi entropy (SRE) – in tree-level $2\to 2$ elastic scatterings. After angular averaging, the RMI (helicity basis) and the SRE (fixed beam basis) exhibit identical dependence on $\sin^2\theta_W$ within each neutral-current channel. We trace this correspondence to a common physical origin that it's the Yukawa mass insertion acts as a $-\mathrm{i}Y$ quantum gate in chirality space. Minimizing entropies across all processes yields $\sin^2\theta_W$ values matching purely axial vector-like couplings in $Z$ boson exchanged channel.