Measurements from the weak charge radius experiments on ${}^{48}\mathrm{Ca}$ (CREX) and ${}^{208}\mathrm{Pb}$ (PREX) challenge existing nuclear models. In the post-PREX-CREX era, it is unclear if current models can simultaneously describe weak charge distributions along with accurate measurements of binding energy and charge radii. In this work, we explore the parameter space of relativistic and nonrelativistic models to study the differences between the electric and weak form factors, $\mathrm{\Delta }F=F_{\text{ch}}-F_W$, in ${}^{48}\mathrm{Ca}$ and ${}^{208}\mathrm{Pb}$. We show, for the first time, which aspects of mean-field models are the most important in determining the relative magnitude of the neutron skin in lead and calcium nuclei. We carefully disentangle the tension between the PREX-2/CREX constraints and the ability of the relativistic mean field and Skyrme models to accurately describe binding energies and charge radii. We find that the nuclear symmetry energy coefficient $S_{\mathrm{V}}$ and the isovector spin-orbit coefficient $b_4^{\prime }$ play different roles in determining $\mathrm{\Delta }F$ of ${}^{48}\mathrm{Ca}$ and ${}^{208}\mathrm{Pb}$. Consequently, adjusting $S_{\mathrm{V}}$ or $b_4^{\prime }$ shifts predicted $\mathrm{\Delta }F$ values toward or away from PREX-2/CREX measurements. Additionally, $S_{\mathrm{V}}$ and the slope $L$ are marginally correlated given the prior constraints of our Bayesian inference, allowing us to infer them separately from PREX-2/CREX data.

In its original formulation, Heisenberg's uncertainty principle describes a trade-off relation between the error of a quantum measurement and the thereby induced disturbance on the measured object. However, this relation is not valid in general. An alternative universally valid relation was derived by Ozawa in 2003, defining error and disturbance in a general concept, experimentally accessible via a tomographic method. Later, it was shown by Hall that these errors correspond to the statistical deviation between a physical property and its estimate. Recently, it was discovered that these errors can be observed experimentally when weak values are determined through a procedure named “feedback compensation.” Here, we apply this procedure for the complete experimental characterization of the error-disturbance relation between a which-way observable in an interferometer and another observable associated with the output of the interferometer, confirming the theoretically predicted relation. As expected for pure states, the uncertainty is tightly fulfilled.

The understanding of a dynamical system's properties can be significantly advanced by establishing it as a Hamiltonian system and then systematically exploring its inherent symmetries. By formulating agents’ strategies and cumulative payoffs as canonically conjugate variables, we identify the Hamiltonian function that generates the dynamics of polymatrix zero-sum games. We reveal the symmetries of our Hamiltonian and derive the associated conserved quantities, showing how the conservation of probability and the invariance of the Fenchel coupling are intrinsically encoded within the system. Furthermore, we propose the dissipation Follow-the-Regularized-Leader (DFTRL) dynamics by introducing a perturbation that dissipates the Fenchel coupling, proving convergence to the Nash equilibrium and linking DFTRL to last-iterate convergent algorithms. Our results highlight the potential of Hamiltonian dynamics in uncovering the structural properties of learning dynamics in games and pave the way for broader applications of Hamiltonian dynamics in game theory and machine learning.

We demonstrate that open quantum systems exhibiting dynamical phase transitions (DPTs) allow for efficient protocols implementing the Pontus-Mpemba effect. The relaxation speedup toward a predesignated target state is tied to the existence of a long metastable time window preceding the DPT and can be exploited in applications to systematically optimize quantum protocols. As paradigmatic example for the connection between DPTs and quantum Mpemba effects, we study one-dimensional interacting lattice fermions corresponding to a dissipative variant of the Gross-Neveu model.

Periodically driven systems intertwined with non‐Hermiticity open a rich arena for topological phases that transcend conventional Hermitian limits. The physical significance of these phases hinges on obtaining the topological invariants that restore the bulk‐boundary correspondence, a task well explored for static non-Hermitian (NH) systems, while it remains elusive for the driven scenario. Here, we address this problem by constructing a generalized Floquet non‐Bloch framework that analytically captures the spectral and topological properties of time-periodic NH systems. Employing a high-frequency Magnus expansion, we analytically derive an effective Floquet Hamiltonian and formulate the generalized Brillouin zone for a periodically driven quasi-one-dimensional system, namely, the Creutz ladder with a staggered complex potential. Our study demonstrates that the skin effect remains robust (despite the absence of nonreciprocal hopping) across a broad range of driving parameters, and is notably amplified in the low-frequency regime due to emergent longer-range couplings. We further employ a symmetric time frame approach that generates chiral-partner Hamiltonians, whose invariants, when appropriately combined, account for the full edge-state structure. To substantiate the theoretical framework, we propose a topolectrical circuit (TEC) that serves as a viable experimental setting. Apart from capturing the skin modes, the proposed TEC design faithfully reproduces the presence of distinct Floquet edge states, as revealed through the voltage and impedance profiles, respectively. Thus, our work not only offers a theoretical framework for exploring NH-driven systems but also provides an experimentally feasible TEC architecture for realizing these phenomena stated above in a laboratory.

An optomechanical system of fundamental importance consists of two intercoupled mechanical resonators, which are radiation-pressure coupled individually to a photonic cavity. This closed-loop and overall lossy configuration possesses two exceptional points (EPs) and offers the realization of synthetic magnetism, controlled by the loop phase. To elucidate the intricate role of loop phase and EPs in this setting, we analyze the noise power spectral density profiles of internal as well as output fluctuations. In the presence of a synthetic magnetic field, the nonreciprocal routing of a signal is well known. Here, we further show that this also applies to nonreciprocal backaction noise flow when the time-reversal symmetry is broken, while the Onsager-Casimir symmetry still holds. To better quantify this phenomenon, we introduce a nonreciprocity measure that contrasts the time-reversed counterparts as a function of loop phase. We observe that nonreciprocal noise flow is enhanced for smaller intermechanical couplings at the expense of lower sensitivity, whereas for sensing purposes, using a higher intermechanical coupling constant is the more viable option.

The Edelstein effect is a promising mechanism for generating spin and orbital polarization from charge currents in systems without inversion symmetry. In ferroelectric materials, such as germanium telluride (GeTe), the combination of bulk Rashba splitting and voltage-controlled ferroelectric polarization provides a pathway for electrical control of the sign of the charge-spin conversion. In this work, we investigate current-induced spin and orbital magnetization in bulk GeTe using Wannier-based tight-binding models derived from ab initio calculations and semiclassical Boltzmann theory. Employing the modern theory of orbital magnetization, we demonstrate that the orbital Edelstein effect entirely dominates its spin counterpart. This difference is visualized through the spin and orbital textures at the Fermi surfaces, where the orbital moment surpasses the spin moment by one order of magnitude. Moreover, the orbital Edelstein effect remains largely unaffected in the absence of spin-orbit coupling, highlighting its distinct physical origin compared to the spin Edelstein effect.

When Casimir friction torque acts upon a rotated nanoparticle (NP), mechanical energy can be transformed into thermal energy, known as Casimir radiation, which significantly affects the thermal performance of nanoelectromechanical systems. In this work, we investigate Casimir radiation with nonreciprocal Weyl semimetal (WSM) NP levitated on a plate. WSM NP with inherent nonreciprocity has a radiative heat flux 27 times higher than NP with degenerate modes. The underlying physics is elucidated by the coupling and decoupling of the electromagnetic local density of states between nonreciprocal WSN NP and the plate in the near-field. The threefold localized plasmon modes of WSM NP split into localized circular modes with strong gyrotropic response, which opens up channels for Casimir radiation. This work provides a method for nanoscale energy conversion in NP systems.

Signaling quantum channels are fundamental to quantum communication, enabling the transfer of information from input to output states. In contrast, thermalization erases information about the initial state. This raises a crucial question: How does the thermalizing tendency of a quantum channel constrain its signaling power and vice versa? In this work, we address this question by considering three thermodynamic tasks associated with a quantum channel: the generation, preservation, and transmission of athermality. We provide faithful measures for athermality generation and athermality preservation of quantum channels, and prove that their difference quantifies athermality transmission. Analyzing these thermodynamic tasks, we find that the signaling ability of a quantum channel is upper-bounded by its athermality preservation and lower-bounded by its athermality transmission, thereby establishing a fundamental relationship between signaling and thermodynamic properties of channels for quantum communication. We demonstrate this interplay for the example of the quantum switch, revealing an explicit trade-off between the signaling ability and athermality of the quantum channels it can implement.

For the solution of partial differential equations (PDEs), we show that the quantum Fourier transform (QFT) can enable the design of quantum circuits that are particularly simple, both conceptually and with regard to hardware requirements. This is shown by explicit circuit constructions for the incompressible advection, heat, isotropic acoustic wave, and Poisson's equations as canonical examples. We utilize quantum singular value transformation to develop circuits that are expected to be of optimal computational complexity. Additionally, we consider approximations suited for smooth initial conditions and describe circuits that make lower demands on hardware. The simple QFT-based circuits are efficient with respect to dimensionality and pave the way for current quantum computers to solve high-dimensional PDEs.

Over the past few years, various methods have been developed to engineer and to exploit the dynamics of photonic quantum states as they evolve through linear optical networks. Recent theoretical works have shown that the underlying Lie algebraic structure plays a crucial role in the description of linear optical Hamiltonians, as such formalism identifies intrinsic symmetries within photonic systems subject to linear optical dynamics. Here, we experimentally investigate the role of Lie algebras applied to the context of Boson sampling, a pivotal model to the current understanding of computational complexity regimes in photonic quantum information. Performing experiments of increasing complexity, realized within a fully reconfigurable photonic circuit, we show that sampling experiments do indeed fulfill the constraints implied by a Lie algebraic structure. In addition, we provide a comprehensive picture about how the concept of Lie algebraic invariant can be interpreted from the point of view of $n\mathrm{th}$-order correlation functions in quantum optics. Our work shows how Lie algebraic invariants can be used as a benchmark tool for the correctness of an underlying linear optical dynamics within typical interferometric architectures for photonic quantum information. This opens avenues for the use of algebraic-inspired methods as analysis tools for photon-based quantum computing protocols.

Thermodynamic cost of communication is a major factor in the thermodynamic cost of real-world computers, both biological and digital. Despite its importance, the fundamental principles underlying this cost remain poorly understood. This paper makes two major contributions to addressing this gap. First, we derive a universal relationship between information transmission rate and minimal entropy production by focusing on the mismatch cost component of thermodynamic cost. The resulting relationship holds independently of the underlying physical dynamics, making it broadly applicable. We discuss the implications of the minimal communication cost for work extraction in measurement-and-feedback protocols, and through examples involving binary channels, we show that the relationship between transmission rate and minimal thermodynamic cost can exhibit diminishing returns in certain scenarios. Second, we extend this thermodynamic analysis to the computational front and back ends critical to communication—namely, encoding and decoding to reduce errors in noisy transmission. Using the framework of periodic machines, we establish strictly positive minimal costs for implementing linear error-correcting codes. We compare these costs with end-to-end error rates, highlighting trade-offs between thermodynamic efficiency and decoding accuracy.

Recently, the prospect of guiding charged particles by means of Lagrange points has been put forward. What makes this methodology possible is the action of Coriolis forces that dynamically provide stability in static helicoidal potential landscapes. In such an environment, particle guidance can occur indefinitely with minimal losses, without the need for magnetic fields, in a manner analogous to photon transport in optical fibers. Here, we provide a rigorous stability analysis of the relativistic charged-particle dynamics when launched into a Lagrange waveguide—an aspect crucial in establishing the necessary criteria for stable trapping. By considering all the force components involved, our results delineate the stability boundaries under both attractive and repulsive electrostatic conditions. A first-order perturbation approach yields both the spectral eigenvalues and their corresponding eigenvectors associated with the stability of particle dynamics in a six-dimensional phase space. The Larmor radiation is also investigated in terms of pertinent parameters, along with the radiated energy spectral density. Our results enable the design and realization of this new class of Lagrange systems capable of guiding charged particles across a wide range of energy scales, with potential utility in a broad spectrum of applications.

High-harmonic generation (HHG) is one of the fundamental processes at the heart of attosecond physics. Traditionally viewed as an effective single-particle effect, recent advances have focused on contributions to the harmonic spectrum beyond this single-particle picture, as well as on probing electron correlations through HHG in atoms, molecules, and solids. In this paper, we introduce a reduced density matrix description to explore and to quantify correlation effects on a subcycle timescale and apply this approach to prototypical multielectron atoms. By comparing noble gas atoms (He, Ne) with alkaline-earth atoms (Be, Mg) exposed to driving fields with similar Keldysh parameters, we show that the subcycle variation of correlation parameters differs markedly for noble gases and alkaline-earth atoms. We provide an intuitive explanation of these surprising effects based on the dynamics of natural orbitals and discuss the effect of this ultrafast correlation dynamics on the HHG spectrum.

Landauer’s principle provides a deep connection between information processing and thermodynamics by setting a lower limit on the energy consumption and heat production of logically irreversible transformations. However, Landauer’s original formulation assumes that information is initially stored in an equilibrium state, whereas real devices often operate with out-of-equilibrium states. Here, we experimentally demonstrate that nonequilibrium memory states can provide a useful resource for fast information erasure below the equilibrium bounds by using an underdamped levitated optomechanical system. To that end, we introduce a versatile optical levitation scheme that enables fast and precise dynamical shaping of general potential landscapes. By harnessing the energy and entropy of an initial nonequilibrium two-state memory, we demonstrate reduced power consumption as well as negative heat production during erasure. Our findings significantly broaden the range of tools available in levitodynamics and suggest that the engineering of appropriate far-from-equilibrium memory states could pave the way for an approach to heat management.

Multiplexing information in different degrees of freedom is a natural solution to the scalability bottleneck in optical quantum communications and computing. However, for bulk-optics systems, size, cost, stability, and reliability can make scalability either impractical or highly challenging to implement. We present a framework to engineer continuous and discrete-variable entanglement produced through nondegenerate spontaneous parametric down-conversion in ${\chi }^{\left(2\right)}$ nonlinear photonic lattices in spatial and spectral degrees of freedom that can alleviate the scalability challenge. We show how spatio-spectral pump shaping produces cluster states that are natively distributable in quantum communication networks and a resource for measurement-based quantum computing.

The Heisenberg uncertainty inequality is used to derive a rigorous lower bound to the amount of isospin impurities in $N=Z$ atomic nuclei, caused by the violation of isospin symmetry. The bound is fixed by the difference between the neutron and proton radii and the sum of the charge-exchange monopole strengths. It can be used to check the consistency of advanced many-body calculations accounting for the breaking of isospin symmetry. The uncertainty inequality is also employed to derive an upper bound to the isovector dipole moment in terms of the amount of isospin impurities, providing an insightful connection between the violation of parity and isospin symmetries.