Papers

Angus Walsh, Lorcan Conlon, Biveen Shajilal +5 more·Oct 23, 2025

A core problem in communications is the optimal discrimination of binary-phase-shift-keyed (BPSK) signals. A longstanding goal has been to reach the fundamental quantum limit, known as the Helstrom bound, for BPSK signals encoded in coherent states. ...

Annie Marsden, Liam O'Carroll, Aaron Sidford +1 more·Oct 23, 2025

We consider the problem of minimizing a $d$-dimensional Lipschitz convex function using a stochastic gradient oracle. We introduce and motivate a setting where the noise of the stochastic gradient is isotropic in that it is bounded in every direction...

Margaret Hawton·Oct 22, 2025

We second quantize the Fermi Lagrangian in the Lorenz gauge to obtain a covariant theory of photon quantum mechanics. Number density is real so it is interpreted as position probability density. The Hilbert space is the vector space of fields with no...

Valery Shchesnovich·Oct 22, 2025

Solvable bosonic models provide a fundamental framework for describing light propagation in nonlinear media, including optical down-conversion processes that generate squeezed states of light and their higher-order generalizations. In quantum optics ...

Liron Mor Yosef, Haim Avron·Oct 22, 2025

Over a decade ago, it was demonstrated that quantum computing has the potential to revolutionize numerical linear algebra by enabling algorithms with complexity superior to what is classically achievable, e.g., the seminal HHL algorithm for solving l...

Blas Durá-Azorín, Antonio I. Fernández-Domínguez, Alejandro Manjavacas·Oct 22, 2025

We theoretically investigate the emergence of quantum nonlinearities in the optical response of lattices of two-level quantum emitters coherently driven by a laser. For subwavelength lattice periods, where the system behaves as a quantum metasurface,...

Amit Kam, Kfir Sulimany, Shai Tsesses +1 more·Oct 22, 2025

Encoding in a high-dimensional Hilbert space improves noise resilience in quantum information processing. This approach, however, may result in cross-mode coupling and detection complexities, thereby reducing quantum cryptography performance. This fu...

Adam Fredriksson, Erik Sjöqvist·Oct 22, 2025

The issue of separating Schrödinger-type quantum time evolution into a product of holonomic and dynamical parts in the non-adiabatic non-Abelian case is examined. We identify all special cases in which this kind of separation is possible, and we prov...

C. G. L. Bøttcher, E. Önder, T. Connolly +8 more·Oct 22, 2025

Superconducting qubits are among the most promising platforms for realizing practical quantum computers. One requirement to create a quantum processor is nonlinearity, which in superconducting circuits is typically achieved by sandwiching a layer of ...

Suyash Bajpai, Aviva Lucas-DeMott, Nirosha J Murugan +2 more·Oct 22, 2025

While computational capacity limits of the universe and carbon-based life have been estimated, a stricter bound for aneural organisms has not been established. Physarum polycephalum, a unicellular, multinucleated amoeba, is capable of complex problem...

Chiara Marletto, Vlatko Vedral·Oct 22, 2025

We rebut a recent paper that claims that classical gravity can entangle two massive superpositions by local means. We refute the misconceptions appearing in this paper and confirm that the quantum features are necessary in the gravitational field if ...

Simon Martin, Marcin Raczkowski, Fakher F. Assaad +1 more·Oct 22, 2025

A multichannel Kondo system, where a single quantum spin couples to multiple channels of an electronic bath, provides one of the simplest examples of a zero-dimensional non-Fermi liquid. It is natural to ask: what happens when an extensive number of ...

Jens Eisert, John Preskill·Oct 22, 2025

Quantum computing is advancing rapidly, yet substantial gaps separate today's noisy intermediate-scale quantum (NISQ) devices from tomorrow's fault-tolerant application-scale quantum (FASQ) machines. We identify four related hurdles along the road ah...

Byoungjoon Ahn, Jaydeep Kumar Basak, Keun-Young Kim +3 more·Oct 22, 2025

We introduce generalization of the recently proposed Latent Entropy (L-entropy) [1] as a refined measure of genuine multipartite entanglement (GME) in pure states of $n$-party quantum systems. Generalized L-entropy satisfies the axioms required for a...

Xiaolin Ma, Volodymyr Takhistov, Norikazu Mizuochi +1 more·Oct 22, 2025

Quantum sensing with qubits has advanced fundamental physics searches, but higher dimensional systems offer untapped potential. We present a universal qutrit framework that yields a sequence-independent fourfold increase in quantum Fisher information...

Simone Cavazzoni, Giovanni Ragazzi, Paolo Bordone +1 more·Oct 22, 2025

The maximum work that can be extracted from a quantum battery is bounded by the ergotropy of the system, which is determined by the spectral properties of the Hamiltonian. In this paper, we employ the formalism of quantum walks to investigate how the...

Aritra Ghosh, Nilamoni Daloi, M. Bhattacharya·Oct 22, 2025

We theoretically propose a quantum heat engine using a setup consisting of a ring-trapped Bose-Einstein condensate placed in a Fabry-Pérot cavity where the optical field carries orbital angular momentum. We first show that the cavity-enhanced light-a...

Veronica Giardini, Luca Guariento, Andrea Fantini +6 more·Oct 22, 2025

We report on the realization of a platform for trapping and manipulating individual $^{88}$Sr atoms in optical tweezers. A first cooling stage based on a blue shielded magneto-optical trap (MOT) operating on the $^1S_0$ -> $^1P_1$ transition at 461 n...

Virgile Guémard·Oct 22, 2025

In this work, we prove that for any $m>1$, there exists a family of good qudit quantum codes supporting transversal logical $\mathsf{C}^{m-1}\mathsf{Z}$ gates that can address specified logical qudits and be largely executed in parallel. Building on ...

Shruti Shirol, Sean van Geldern, Hanzhe Xi +1 more·Oct 22, 2025

Physical qubits in a quantum computer are often represented by superposition states of single particles or excitations. Decay of the excitation itself is a fundamental error channel that is difficult to overcome via external drive or control techniqu...