We develop a finite-temperature Gaussian-state formulation of quantum energy teleportation in the one-dimensional harmonic chain. For Gibbs states, the optimized measurement-feedback protocol reduces to thermal two-point functions. In the single-site protocol, the extracted energy is governed by a s…

[Phys. Rev. A 114, 032433] Published Tue Sep 15, 2026

Continuous-time quantum walks on a lattice spread ballistically and converge to a limiting distribution for the rescaled position. On the hard-wall half line the boundary reflects the walker but does not change the bulk dispersion, so the ballistic front remains set by the maximal group velocity. We…

[Phys. Rev. A 114, 032434] Published Tue Sep 15, 2026

Quantum imaginarity is an important resource in quantum information theory, associated with the operational role of complex numbers in quantum mechanics. Here we investigate how imaginarity behaves under coherent superposition of orthogonal pure states. For orthonormal components, we express the geo…

[Phys. Rev. A 114, 032435] Published Tue Sep 15, 2026

Quantum information processing, communication, and sensing networks are being developed with various qubit platforms that use different encoding schemes. Connecting quantum network nodes to distribute entanglement requires matching photon qubit basis encoding. In this work we implement an interconve…

[Phys. Rev. A 114, 032436] Published Tue Sep 15, 2026

In phase-randomized weak coherent pulse (WCP) implementations of the quantum key distribution (QKD) BB84 protocol, the decoy method is often used to compensate BB84's vulnerability against photon number splitting attacks. However, this typically introduces extra complexities and requirements on expe…

[Phys. Rev. A 114, 032429] Published Mon Sep 14, 2026

Entanglement distillation is the process of converting noisy entangled states into maximally entangled pure states via local operations and classical communication. A long-standing, unresolved question is which entangled states are amenable to distillation, known as the distillability problem. For B…

[Phys. Rev. A 114, 032430] Published Mon Sep 14, 2026

Wigner’s friend thought experiments have long challenged whether measurement outcomes can be absolute; here, the author examines whether even the “free choices” observers make in setting up an experiment can be absolute. By combining the Wigner’s friend scenario with the Pusey–Barrett–Rudolph theorem on the reality of the quantum state, the author derives a no-go result suggesting that any resolution to extended Wigner’s friend paradoxes that abandons absoluteness must also incorporate a relational nature for free choices.

[Phys. Rev. A 114, 032431] Published Mon Sep 14, 2026

We investigate the private capacity of quantum channels using the recently proposed quantum convolution theory for discrete-variable quantum systems. We focus on the role played by magic resources in this framework. First, for a broad class of convolutional channels, we find that the private capacit…

[Phys. Rev. A 114, 032432] Published Mon Sep 14, 2026

Building on hybrid quantum lattice gas algorithm, we revisit the possibilities of this quantum lattice model. By deriving a correction to the predicted viscosity, we provide analytical and numerical results that refine original formulation. We introduce a minimal two-dimensional generalization of th…

[Phys. Rev. A 114, 032426] Published Thu Sep 10, 2026

Superconducting circuits exhibit remarkable potential for constructing large-scale quantum simulation and computation systems, featuring numerous qubits, extended coherence time, and precise control. Nevertheless, the growing number of signal cables poses a challenge in dilution refrigerators due to…

[Phys. Rev. A 114, 032427] Published Thu Sep 10, 2026

The authors present a combined theoretical and experimental advance showing that $d$+1 projective measurement bases suffice for complete quantum-state tomography in any finite dimension, without relying on mutually unbiased bases. They demonstrate the scheme on a silicon photonic chip, achieving fidelities above 0.96.

[Phys. Rev. A 114, 032428] Published Thu Sep 10, 2026

Bell measurements (BMs) are ubiquitous in quantum information and technology. They are basic elements for quantum commmunication, computation, and error correction. In particular, when performed on logical qubits encoded in physical photonic qubits, they allow for a read-out of stabilizer syndrome i…

[Phys. Rev. A 114, 032421] Published Wed Sep 09, 2026

Discrete time crystals are nonequilibrium states of periodically driven quantum matter characterized by robust subharmonic responses. We investigate how such temporal order behaves in the presence of stochastic measurements. Using trajectory-resolved simulations of a monitored Floquet-Ising model, w…

[Phys. Rev. A 114, 032422] Published Wed Sep 09, 2026

Quantum information masking (QIM) encodes single-qubit information into bipartite entanglement, but the absence of a universal masker restricts standard bipartite implementations to specific Bloch sphere disks. Here, we experimentally demonstrate an automated quantum masking machine that can be reco…

[Phys. Rev. A 114, 032423] Published Wed Sep 09, 2026

Logical operations are essential for quantum computation within quantum error-correcting codes. However, discovering their physical realizations is challenging, especially for nonadditive codes that lack a stabilizer description. We present a general learning-based framework that, given only an enco…

[Phys. Rev. A 114, 032424] Published Wed Sep 09, 2026

Quantum simulation is a promising application for quantum computing. Quantum simulation algorithms may require the ability to control the time evolution unitary. Naive techniques to control a unitary can substantially increase the required computational resources. A standard approach to controlling …

[Phys. Rev. A 114, 032425] Published Wed Sep 09, 2026

The ability to engineer and control quantum states of many-body systems is a central challenge in quantum information science. For a register of $N$ qubits, the full Hilbert space dimension grows exponentially as $2^N$, rendering generic state preparation and control infeasible without exploiting structu…

[Phys. Rev. A 114, 032412] Published Tue Sep 08, 2026

Because ideal Gottesman-Kitaev-Preskill (GKP) states are invariant under stabilizers, researchers often assume that measuring a state’s stabilizers directly quantifies its closeness to an ideal GKP state. In fact, the author shows that high stabilizer expectation values only provide an upper bound on proximity, and that states far from an ideal GKP state can still yield excellent stabilizer expectation values.

[Phys. Rev. A 114, 032413] Published Tue Sep 08, 2026

Spin ensembles are promising quantum technological platforms, but their utility relies on the ability to perform quantum error correction (QEC) for decoherences in these systems. Typical QEC for ensembles requires addressing individually resolved qubits, but this is practically challenging in most r…

[Phys. Rev. A 114, 032414] Published Tue Sep 08, 2026

The evolution of a quantum system under time-dependent driving exhibits phenomena that are absent in its stationary counterpart. However, the high dimensionality and noncommutative nature of quantum dynamics make this a challenging problem. The Magnus expansion provides an analytic framework to appr…

[Phys. Rev. A 114, 032415] Published Tue Sep 08, 2026

Bipartite entanglement purification is the conversion of copies of weakly entangled pairs shared between two separated parties into a smaller number of strongly entangled shared pairs using only local operations and classical communication. Choosing between different entanglement purification protoc…

[Phys. Rev. A 114, 032416] Published Tue Sep 08, 2026

Quantum digital signatures (QDSs) utilize shared keys generated by quantum key distribution, thereby providing information-theoretic security. Most existing QDS schemes, however, only support single-signer scenarios, which limits their applications in large-scale quantum networks. Based on previous …

[Phys. Rev. A 114, 032417] Published Tue Sep 08, 2026

Quantum metrology exploits quantum resources to achieve measurement precision beyond classical scaling, but this advantage is often compromised by environmental decoherence. While dynamical decoupling is a powerful tool for eliminating non-Markovian noise, it has a fundamental conflict: The decoupli…

[Phys. Rev. A 114, 032418] Published Tue Sep 08, 2026

Simulating computationally hard fermionic systems is a promising application of quantum computing. However, mapping nonlocal fermionic operators to qubits often produces deep circuits, rendering such simulations impractical on near-term hardware. We introduce two Majorana swap network compilation st…

[Phys. Rev. A 114, 032419] Published Tue Sep 08, 2026

Quantum state preparation is an important subroutine in many quantum algorithms. The goal is to encode classical information directly to the quantum state so that it is possible to leverage quantum algorithms for data processing. However, quantum state preparation of arbitrary states scales exponent…

[Phys. Rev. A 114, 032420] Published Tue Sep 08, 2026

We present a quantum computation approach in which computation is guided by positive-operator-valued-measure (POVM) measurements following a given computation path in multisteps. In this approach, one ancillary qubit is coupled to a register of working qubits, and a POVM measurement is implemented e…

[Phys. Rev. A 114, 032408] Published Fri Sep 04, 2026

We initiate an investigation into a notion of state complexity for discrete-variable quantum systems. Specifically, we propose an information-theoretic quantifier for the complexity of quantum states within the stabilizer formalism of quantum computation. This is achieved by leveraging the symmetric…

[Phys. Rev. A 114, 032409] Published Fri Sep 04, 2026

We propose the first continuous-variable (CV) unclonable encryption scheme, extending the paradigm of quantum encryption of classical messages to CV systems. In our construction, a classical message is first encrypted classically and then encoded using an error-correcting code. Each bit of the codew…

[Phys. Rev. A 114, 032410] Published Fri Sep 04, 2026

A protocol for identifying controlled-not (cnot) gates versus single-qubit-only gates in universal quantum circuits using randomized input states was recently shown to be intimately connected to the quantum resource of state texture. Here, we revisit this gate identification protocol and demonstrate…

[Phys. Rev. A 114, 032411] Published Fri Sep 04, 2026

We consider the problem of identifying the quantum spin states that are the optimal sensors of a given transformation, averaged over all possible orientations of the spin system. Our geometric approach to the problem is based on a fidelity criterion and is entirely general, encompassing any unitary …

[Phys. Rev. A 114, 032406] Published Thu Sep 03, 2026

We investigate the performance of the charger-mediated quantum battery modeled by a two-qubit system. One of the qubits acts as the battery and the other acts as the charger, which is subjected to a reservoir. We derive the time-local master equation in Lindblad form with a time-dependent dephasing …

[Phys. Rev. A 114, 032407] Published Thu Sep 03, 2026

We address the task of converting $n$ uses of an unknown unitary transformation into a quantum state (i.e., storage) and later retrieval of the transformation. Specifically, we consider the case where the unknown unitary is selected with equal prior probability from two options. First, we prove that t…

[Phys. Rev. A 114, 032404] Published Wed Sep 02, 2026

We study a modified fixed-point version of the quantum approximate optimization algorithm (fpQAOA), where parameters are trained classically on small instances and then transferred to larger problems. Our scheme combines three ingredients: (i) targeting approximate solutions via a prescribed approxi…

[Phys. Rev. A 114, 032405] Published Wed Sep 02, 2026

Long-lived waiting-time beatings in two-dimensional electronic spectroscopy remain puzzling in strongly dephasing regimes, where excitonic coherence is expected to decay rapidly. These oscillations are often attributed to environmental memory, typically modeled by resonance with a discrete mode. Her…

[Phys. Rev. A 114, 032401] Published Tue Sep 01, 2026

Traditional Bell state measurement (BSM) and the product basis measurement (PBM) have been integral to nearly the entire development of quantum computing. Unlike the BSM and the PBM, a recently proposed two-qubit joint measurement called the elegant joint measurement (EJM) exhibits novel tetrahedral…

[Phys. Rev. A 114, 032402] Published Tue Sep 01, 2026

Building on the framework developed by Meng et al. [Sci. Adv. 8, eabm7585 (2022)], we present an analytical study of a measurement-record-based state estimation method for a mechanical oscillator serving as one end mirror of a detuned-cavity system. Unlike conventional approaches, this method enable…

[Phys. Rev. A 114, 032403] Published Tue Sep 01, 2026

A universal method for block encoding the Liouville representation of quantum channels is presented, enabling the manipulation of the spectrum of unknown quantum channels.

[Phys. Rev. A 114, L030401] Published Tue Sep 01, 2026

Quantum annealing correction (QAC) models provide a promising approach for mitigating errors in quantum annealers. Previous studies have established that QAC models are crucial for ensuring the robustness of the ground state of the Ising model on hardware. In this work, the effects of QAC models inc…

[Phys. Rev. A 114, 022470] Published Mon Aug 31, 2026

Simulating chemical reactions exhibits a pronounced unevenness in computational difficulty: While equilibrium reactant and product geometries are often tractable, transition-state (TS) geometries frequently display strong multireference character that challenges both classical solvers and coherent q…

[Phys. Rev. A 114, 022471] Published Mon Aug 31, 2026

Nonadiabatic holonomic quantum computation (NHQC) offers intrinsic resilience to certain control imperfections. However, conventional nonadiabatic holonomic protocols are constrained by the fixed-pulse-area condition, which limits flexibility and prolongs duration of small-angle gates. Here we exper…

[Phys. Rev. A 114, 022472] Published Mon Aug 31, 2026

Dissipative phase transitions are strongly shaped by the symmetries of the Liouvillian, yet a clear understanding of the quantitative impact of weak and strong symmetries on critical behavior is presently lacking. We study a squeezed-photon model with single- and two-photon losses, realizing weak an…

[Phys. Rev. A 114, 022469] Published Fri Aug 28, 2026

Many-body quantum systems with local interactions undergo “sudden death of entanglement” at high temperatures, whereby thermal states become classical mixtures of product states. We investigate whether symmetry constraints can prevent this phenomenon. We prove that strongly symmetric thermal states …

[Phys. Rev. A 114, 022458] Published Thu Aug 27, 2026

In this work we investigate the effect of decomposition basis on primitive qudit gates on superconducting radio-frequency cavity-based quantum computers with applications to lattice gauge theory. Three approaches are tested: snap and displacement gates, ecd and single-qubit rotations $R(\theta ,\varphi )$, and opt…

[Phys. Rev. A 114, 022460] Published Thu Aug 27, 2026

Quantum error correction is essential for fault-tolerant quantum computation, yet most existing codes rely on local control and stabilizer measurements that are difficult to implement in systems dominated by collective interactions. Inspired by S. Omanakuttan and T. J. Volkoff, Spin-squeezed Gottesm…

[Phys. Rev. A 114, 022467] Published Thu Aug 27, 2026

We develop a general perturbation theory for the local quantum uncertainty (LQU), a discord-type quantifier of nonclassicality based on the Wigner-Yanase skew information. Starting from a perturbed density matrix $\rho ={\rho }_0+\epsilon {\rho }_1$, we derive an explicit first-order expansion of ${\rho }^{1/2}$ using an integral represe…

[Phys. Rev. A 114, 022468] Published Thu Aug 27, 2026

Thermal engines have been one of the principal topics of thermodynamics ever since its beginning. Today, in the era of the second quantum revolution, although the thermal processes in constant temperatures are relatively well understood in the language of resource theories, a framework to describe t…

[Phys. Rev. A 114, 022461] Published Wed Aug 26, 2026

Based on two types of channel divergences, we introduce four kinds of dynamical imaginarity measures, defined respectively by the deviation of a quantum channel from the set of real channels and from its conjugate channel. We show that they satisfy the desirable properties for a valid dynamical imag…

[Phys. Rev. A 114, 022462] Published Wed Aug 26, 2026

Higher-dimensional quantum systems, such as qudits, offer architectural and algorithmic advantages over qubits, but their increased spectral crowding and limited controllability render high-fidelity quantum gates particularly challenging. We propose a hybrid optimization framework that integrates op…

[Phys. Rev. A 114, 022463] Published Wed Aug 26, 2026

As emerging quantum architectures evolve into heterogeneous networks combining different physical substrates, such as qubits for logic and higher-dimensional qudits for robust communication, the traditional scalar metrics of quantum error correction become insufficient. To address this, we introduce…

[Phys. Rev. A 114, 022464] Published Wed Aug 26, 2026

Informationally complete measurements form the foundation of universal quantum state reconstruction, while quantum parameter estimation is based on the local structure of the manifold of quantum states. In this work, we establish a link between these two aspects within the context of a single inform…

[Phys. Rev. A 114, 022465] Published Wed Aug 26, 2026

We determine the optimal information-disturbance tradeoff for estimating an unknown spatial direction encoded in two antiparallel spins. Rotational covariance reduces the optimization over all instruments to a finite-dimensional Choi problem: a positive seed operator obeys one trace constraint for e…

[Phys. Rev. A 114, 022466] Published Wed Aug 26, 2026

In developing quantum science and technologies, it is essential to demonstrate so-called quantum advantages, which are performances that can be achieved only with the assistance of quantum resources. Most of the time, different quantum features lead to different advantages. Interestingly, there are …

[Phys. Rev. A 114, 022456] Published Tue Aug 25, 2026

The experimental access to ultrastrong couplings in light-matter interactions has made the quantum phase transition (QPT) in the quantum Rabi model practically relevant, while the physics of the QPT has not yet been fully explored. The polaron picture is a method capable of analyzing in the entire c…

[Phys. Rev. A 114, 022457] Published Tue Aug 25, 2026

We define and study the properties of squeezed quantum multiplets, which are sets of $D$-orthonormal quantum states formed by superpositions of states squeezed along $D$ equally spaced directions in quadrature space. We present analytical expressions for phase-space distributions (Wigner and characteris…

[Phys. Rev. A 114, 022459] Published Tue Aug 25, 2026

We propose a witness of temporal quantum entanglement using the imaginary component of the complex heat capacity—a measurable thermodynamic quantity in temperature-modulated calorimetry. By establishing a direct correspondence between complex heat capacity and the pseudodensity matrix formalism, our…

[Phys. Rev. A 114, 022448] Published Mon Aug 24, 2026

Decoders of quantum error correction (QEC) experiments make decisions based on detected errors and the expected rates of error events, which together comprise a detector error model. Here we show that the syndrome history of QEC experiments is sufficient to correct coherent errors, removing the need…

[Phys. Rev. A 114, 022449] Published Mon Aug 24, 2026

Recently, Yamaguchi and Kempf proved that encrypted qubits can be cloned. In this work we generalize the encrypted cloning protocol and prove that it also applies to higher-order quantum systems. Given that a straightforward generalization of the protocol using the exponential of the shift and phase…

[Phys. Rev. A 114, 022450] Published Mon Aug 24, 2026

A hybrid quantum system comprising semiconductor spin qubits and superconducting resonators offers a practical route toward scalable quantum information processing. Achieving a high-fidelity entangling gate between spatially separated spin qubits is, however, both crucial and challenging. Here, we i…

[Phys. Rev. A 114, 022451] Published Mon Aug 24, 2026

Various entanglement percolation protocols provide distinct statistical-physics frameworks for analyzing the capability of quantum networks (QNs) to achieve long-distance entanglement distribution. The percolation efficiencies and critical exponents exhibited by different existing protocols vary con…

[Phys. Rev. A 114, 022452] Published Mon Aug 24, 2026

Recent studies have shown that Bargmann invariants provide effective detectors of set imaginarity. In this paper, we investigate set imaginarity as a quantum resource in qubit systems. By exploiting the structure of Bargmann invariants, we show that the free operations for qubit set imaginarity cons…

[Phys. Rev. A 114, 022453] Published Mon Aug 24, 2026

The space $\mathrm{Inv}(j_1,j_2,j_3,j_4)$ of SU(2)-invariant four-valent tensors, also known as intertwiners, can be understood as the quantum states of a tetrahedron in Euclidean space with fixed areas. In loop quantum gravity, they are states of what could be called the smallest atom of space with nonzero volume…

[Phys. Rev. A 114, 022454] Published Mon Aug 24, 2026

Dark and subradiant states have emerged as promising resources for stabilizing open quantum batteries against dissipation, but existing studies are largely limited to qubit ensembles and symmetry-based constructions. Here, we introduce a systematic, thermodynamically consistent framework for identif…

[Phys. Rev. A 114, 022455] Published Mon Aug 24, 2026

We analyze a Rydberg gate design based on the original $\pi -2\pi -\pi$ protocol [Jaksch et al., Phys. Rev. Lett. 85, 2208 (2000)] that is modified to enable high-fidelity operation without requiring a strong Rydberg interaction. The gate retains the $\pi -2\pi -\pi$ structure with an additional detuning added to the $2\dots$

[Phys. Rev. A 114, 022447] Published Fri Aug 21, 2026

We develop a comprehensive quantum estimation framework to quantify how precisely gravitationally induced decoherence can be inferred in optomechanical systems, using single-mode Gaussian probe states. Our approach combines a microscopic description of the gravitational diffusion mechanism with quan…

[Phys. Rev. A 114, 022442] Published Thu Aug 20, 2026

Understanding the limitations imposed by noise on current and next-generation quantum devices is a crucial step toward demonstrating practical quantum advantage. In this work, we investigate the accumulation of entropy density as a benchmark to monitor the performance of quantum processing units (QP…

[Phys. Rev. A 114, 022443] Published Thu Aug 20, 2026

We present a quantum-native framework for auxiliary-field quantum Monte Carlo (AFQMC), viewed as imaginary-time projection for ground-state calculation through an ensemble of one-body propagators driven by stochastic auxiliary fields. Starting from a Feynman-Kac representation, each trajectory is co…

[Phys. Rev. A 114, 022444] Published Thu Aug 20, 2026

We formulate a spatial extension of the Leggett-Garg inequality by considering three distant observers locally measuring a many-body system at three subsequent times. The spatial form is especially suitable to test the ability of quantum devices to generate spatiotemporal correlations in a Hamiltoni…

[Phys. Rev. A 114, 022446] Published Thu Aug 20, 2026

In quantum many-body dynamics, locally encoded information typically scrambles across the entire system, becoming inaccessible to local probes. The upper bound of accessible information of local probes can be characterized by the Holevo information via optimal measurement. In this work, we investiga…

[Phys. Rev. A 114, 022438] Published Wed Aug 19, 2026

Building scalable quantum networks relies on the core device of quantum memory. Most quantum cryptography protocols utilize nonorthogonal state encoding, inevitably causing efficiency loss due to mismatch of base vectors. The orthogonal state encoding protocol, proposed by Goldenberg and Vaidman [Ph…

[Phys. Rev. A 114, 022439] Published Wed Aug 19, 2026

We use a quantum formalism for the partition function of the classical $XY$ model to identify a resilience phase transition in the zero-syndrome postselected sector of a noisy toric-rotor code. To this end, we consider a logical state of toric-rotor code under phase-shift noise described by a von Mise…

[Phys. Rev. A 114, 022440] Published Wed Aug 19, 2026

We present an extended-algebra (EA) control workflow for fixed-horizon, bounded-amplitude quantum control. The method optimizes a state-transfer trajectory in a polynomial EA, projects the optimized lifted trajectory to native physical controls using a budgeted dictionary of product-formula approxim…

[Phys. Rev. A 114, 022441] Published Wed Aug 19, 2026

Bosonic Gaussian thermal states form a fundamental class of states in quantum information science. This paper explores the information geometry of these states, focusing on characterizing the distance between two nearby states and the geometry induced by a parametrization in terms of their mean vect…

[Phys. Rev. A 114, 022437] Published Tue Aug 18, 2026

Classical simulations of noisy quantum circuits are instrumental to our understanding of the behavior of real-world quantum systems and the identification of regimes where one expects quantum advantage. In this work, we present a highly parallelizable tensor-network-based classical algorithm, equipp…

[Phys. Rev. A 114, 022430] Published Mon Aug 17, 2026

The entanglement entropy (EE) of any bipartition of a pure state can be approximately expressed as a sum of entanglement links (ELs). In this work, we introduce their exact extension, i.e., the entanglement hyperlinks (EHLs), a type of generalized mutual information defined through the inclusion-exc…

[Phys. Rev. A 114, 022431] Published Mon Aug 17, 2026

We investigate the mechanisms of energy transfer and distribution in quantum batteries composed of multiple two-level battery cells within the single-excitation subspace. By employing the continuous-time quantum walk, we analyze how energy and ergotropy evolve dynamically under three representative …

[Phys. Rev. A 114, 022432] Published Mon Aug 17, 2026

The authors extend analytical derivations for expectation value distributions to random mixed quantum states and general measurement operator sets, using a combinatorics framework to calculate their moments. Using simulated noisy brickwork circuits, they introduce an effective global depolarizing model that accounts for empirical peak behaviors and reveal that non-symmetric measurement sets yield distinct multimodal distributions.

[Phys. Rev. A 114, 022434] Published Mon Aug 17, 2026

Network quantum steering characterizes the correlations among parties in a quantum network with different levels of trust. It is closely related to the distribution of trusted and untrusted parties, and can be detected by the violation of some steering inequalities. However, different methods of con…

[Phys. Rev. A 114, 022435] Published Mon Aug 17, 2026

Grover's algorithm is a fundamental quantum algorithm that achieves a quadratic speedup for unstructured search problems of size $N$. Recent studies have reformulated this task as a maximization problem on the unitary manifold and solved it via linearly convergent Riemannian gradient ascent methods, r…

[Phys. Rev. A 114, 022436] Published Mon Aug 17, 2026

Accurate quantum channel parameter estimation is essential for effective information reconciliation in continuous-variable quantum key distribution (CV-QKD). However, conventional maximum likelihood (ML) estimators rely on a large amount of disclosed data, leading to a significant loss in symbol eff…

[Phys. Rev. A 114, 022429] Published Fri Aug 14, 2026

Searching for degenerate ground spaces in quantum many-body systems is central to understanding spontaneous symmetry breaking and topological order. Although existing numerical methods can approximate individual ground states with high accuracy, recovering the full degenerate space remains a substan…

[Phys. Rev. A 114, 022428] Published Thu Aug 13, 2026

The authors present a geometric approach to designing robust, simultaneous control pulses that approach the time-energy uncertainty limit. Robustness against errors in background fields, pulse area and coil alignment is demonstrated on colocated nuclear spin ensembles; due to the geometric nature of the approach it should be readily extensible to other pairs of qubits.

[Phys. Rev. A 114, L020401] Published Thu Aug 13, 2026

Adiabatic reverse annealing (ARA) has been proposed as an improvement to conventional quantum annealing for solving optimization problems, in which one takes advantage of an initial guess at the solution to suppress problematic phase transitions. Here we interpret the performance of ARA through its …

[Phys. Rev. A 114, 022422] Published Wed Aug 12, 2026

The Grover lower bound for the unstructured search problem can be surpassed when some information about the data structure is available. Here, we numerically observe that reinforcement can exponentially reduce the number of required evolution layers from $\sqrt{D}$ to $lnD$ in a $D$-dimensional system, by exploi…

[Phys. Rev. A 114, 022423] Published Wed Aug 12, 2026

Random circuits giving rise to unitary designs are key tools in quantum information science and many-body physics. In this work, we investigate a class of random quantum circuits with a specific gate structure. Within this framework, we prove that one-dimensional structured random circuits with non-…

[Phys. Rev. A 114, 022424] Published Wed Aug 12, 2026

Trapped-ion lattice geometries, which determine the interactions between trapped-ion qubits, are typically governed by the balance of Coulomb repulsion forces with the external trapping potential. Here we demonstrate how the effective ion lattice geometry and resulting qubit-qubit interactions may b…

[Phys. Rev. A 114, 022425] Published Wed Aug 12, 2026

It is often argued that two linearly coupled quantum harmonic oscillators, even when cooled to their ground state, display no inherently quantum features beyond quantized energy levels. Here, we challenge this view by showing that their classical observables encode genuinely quantum features. In par…

[Phys. Rev. A 114, 022426] Published Wed Aug 12, 2026

Finite local Hilbert-space truncations arise naturally in quantum simulations of lattice field theories and motivate qudit encodings, but their fault-tolerant advantage over qubit encodings remains unclear. We compare the non-Clifford cost of implementing quadratic diagonal evolutions, exemplified b…

[Phys. Rev. A 114, 022427] Published Wed Aug 12, 2026

Irreversibility and time-translation symmetry are both fundamental in open quantum dynamics, and it is of great importance to study the interplay between them. In this paper, we study tabletop reversibility (TTR) for phase-covariant quantum operations and obtain sharply different conclusions for fin…

[Phys. Rev. A 114, 022419] Published Tue Aug 11, 2026

We investigate the charging dynamics and thermodynamic performance of a wireless quantum battery system mediated by a common structured bosonic environment. By employing a unified resource-theoretic analysis, we elucidate the distinct roles of non-Markovian memory effects and coupling symmetry in re…

[Phys. Rev. A 114, 022420] Published Tue Aug 11, 2026

While there is strong evidence for advantages of quantum over classical computation, the repertoire of computational primitives with proven or conjectured quantum advantage remains limited. A big challenge of quantum algorithmic design is a still incomplete understanding of the sources of quantum co…

[Phys. Rev. A 114, 022421] Published Tue Aug 11, 2026

Magic state distillation (MSD) is a cornerstone of fault-tolerant quantum computing, enabling non-Clifford gates via state injection into stabilizer circuits. However, the substantial overhead of current MSD protocols remains a major obstacle to scalable implementations. We propose a general framewo…

[Phys. Rev. A 114, 022415] Published Mon Aug 10, 2026

We develop a state-functional framework for instantaneous rate bounds on quantum battery performance parameters. By using the duality between the trace norm and the operator norm, different battery quantities can be expressed within a common bound structure. Energetic, extractable work, and informat…

[Phys. Rev. A 114, 022416] Published Mon Aug 10, 2026

We show that a parametrized quantum neural network can be used to build a nonparametric quantum kernel for machine learning that inherits the concentration properties of the neural network cost function. This construction establishes a rigorous connection between barren plateaus (BPs) in variational…

[Phys. Rev. A 114, 022417] Published Mon Aug 10, 2026

Quantum generative models exploit quantum superposition and entanglement to enhance learning efficiency for both classical and quantum data. Recently, inspired by classical diffusion frameworks, the quantum denoising diffusion probabilistic model has emerged as a powerful tool for learning correlate…

[Phys. Rev. A 114, 022418] Published Mon Aug 10, 2026

Prime factorization on quantum processors is typically implemented either via circuit-based approaches such as Shor's algorithm or through analog methods based on adiabatic, annealing, or variational techniques. While Shor's algorithm demands high-fidelity quantum gates, Hamiltonian optimization sch…

[Phys. Rev. A 114, 022413] Published Fri Aug 07, 2026

Implementing time-evolution operators in shallow quantum circuits is important for quantum simulations. The standard method of Trotterization requires a large number of gates to achieve practical accuracy. Variational quantum simulation (VQS) is an algorithm that calculates the time evolution of a q…

[Phys. Rev. A 114, 022414] Published Fri Aug 07, 2026

We investigate bipartite entanglement in qubit hypergraph states across an arbitrary fixed bipartition. Using the real equally weighted representation, the Schmidt rank across the cut can be computed as the real rank of a phase-cleaned cross-cut sign matrix. Whereas graph states admit an exact cut-r…

[Phys. Rev. A 114, 022410] Published Thu Aug 06, 2026

The authors present a device-independent protocol for characterizing unsharp quantum instruments using an entanglement‑assisted code with restricted classical communication between two parties. They experimentally demonstrate the predicted enhancement in decoding probability by implementing tunable unsharp measurements with a Mach-Zehnder interferometer.

[Phys. Rev. A 114, 022411] Published Thu Aug 06, 2026

We show an explicit $N$-qubit protocol involving one-axis-twisted spin squeezed states that allows for simultaneous phase and dephasing strength estimation with precision that asymptotically matches fundamental quantum metrological bounds. The relevance of the protocol goes beyond this particular mode…

[Phys. Rev. A 114, 022412] Published Thu Aug 06, 2026

Understanding the fundamental limits of state convertibility is crucial for establishing the boundaries of quantum information processing and thermodynamic efficiency. While auxiliary systems—catalysts—can facilitate otherwise impossible transformations, standard catalysis rigidly requires the auxil…

[Phys. Rev. A 114, 022407] Published Wed Aug 05, 2026