Accurate precipitation forecasting is becoming increasingly important in the context of climate change. In response, machine learning-based approaches have recently gained attention as an emerging alternative to traditional methods such as numerical weather prediction and climate models. Nonetheless, many recent approaches still rely on off-the-shelf loss functions, and even the more advanced ones merely involve optimization processes based on the critical success index (CSI). The problem, however, is that CSI may become ineffective during extended dry periods when precipitation remains below the threshold, rendering it less than ideal as a criterion for optimization. To address this limitation, we introduce a simple penalty expression and reinterpret it as a quadratic unconstrained binary optimization (QUBO) formulation. Ultimately, the resulting QUBO formulation is relaxed into a differentiable advanced torrential (AT) loss function through an approximation process. The proposed AT loss demonstrates its superiority through the Lipschitz constant, forecast performance evaluations, consistency experiments, and ablation studies with the operational model.

Quantum cryptographic conferencing (QCC) allows multiple parties to establish common secure keys in quantum networks with information-theoretic security. However, the secure transmission distances of current QCC implementations are still limited to the metropolitan areas. Here, we experimentally demonstrate the three-intensity phase-matching (PM) QCC protocol considering finite-size effects by employing frequency-locking and phase-tracking techniques for three parties. The key distribution capability of the PM QCC protocol is demonstrated in the symmetric fiber channels with the distance from each party to the measurement site up to 100 km. The network adaptability of the PM QCC protocol is demonstrated in asymmetric fiber channels used to simulate fiber channel configurations in real networks. Thus, the feasibility of applying the PM QCC protocol to practical intercity quantum networks with both symmetric and asymmetric channels is verified.

Zero- and two-dimensional crystal defects form in open statistical ensembles, such as the grand canonical, that are usually inaccessible with conventional simulation techniques. This longstanding challenge is overcome with a new Hamiltonian Monte Carlo method that samples energy-biased gradual transformations. The method enables free energy calculations for nonideal point defects and the direct prediction of finite-temperature interface structures.

The strength of metals and alloys increases as grain size decreases due to grain boundary strengthening. This “smaller is stronger” effect has been observed consistently in the microcrystalline, ultrafine-grained, and even nanocrystalline metals with the exception of extremely small grains on the order of $\sim 10\mathrm{nm}$, where grain boundary strengthening breaks down. Here we report a reversed trend in the microcrystalline regime. When subjected to extremely high strain rates, metals with smaller grain sizes become softer. The grain sizes studied here (1–$100\mathrm{\mu }\mathrm{m}$) are several orders of magnitude larger than those associated with the breakdown of the grain boundary strengthening. We attribute this softening behavior to the suppression of ballistic dislocation transport, which, consequently, limits dislocation-phonon drag in smaller grains.

This Letter reports measurements of muon-neutrino disappearance and electron-neutrino appearance and the corresponding antineutrino processes between the two NOvA detectors in the NuMI neutrino beam. These measurements use a dataset with double the neutrino mode beam exposure that was previously analyzed, along with improved simulation and analysis techniques. A joint fit to these samples in the three-flavor paradigm results in the most precise single-experiment constraint on the atmospheric neutrino mass splitting, $\mathrm{\Delta }{m}_{32}^2=2.431_{-0.034}^{+0.036}(-2.479_{-0.036}^{+0.036})\times {10}^{-3}{\mathrm{eV}}^2$ if the mass ordering is normal (inverted). In both orderings, a region close to maximal mixing with ${\sin }^2{\theta }_{23}=0.55_{-0.06}^{+0.02}$ is preferred. The NOvA data show a mild preference for the normal mass ordering with a Bayes factor of 2.4 (corresponding to 70% of the posterior probability), indicating that the normal ordering is 2.4 times more probable than the inverted ordering. When incorporating a 2D $\mathrm{\Delta }{m}_{32}^2-{\sin }^{2}2{\theta }_{13}$ constraint based on Daya Bay data, this preference strengthens to a Bayes factor of 6.6 (87%).

We study the dependence of the $p$-wave contact on the Fermi temperature $T_F$ and reduced temperature $T/T_F$ based on the number of closed-channel molecules. From the anisotropic pattern of dissociated molecules, we resolve the narrow $m=0$ and $m=\pm 1$ dipolar splitting of the $p$-wave Feshbach resonance in ${}^6\mathrm{Li}$, enabling the independent determination of the contact for all three $m$ components. For each component, we identify a near-resonant scaling with $\sqrt{T_F}$, indicating the contribution of the normalized effective range $k_F{R}_{\mathrm{e}}$. In addition, we show that the peak contacts observed near resonance increase as $T/T_F$ is lowered, a trend that is accurately captured by estimates based on the second-order virial expansion. Our results, together with estimates from the $p$-wave virial expansion, provide a route toward a complete understanding of the thermodynamics of resonantly enhanced $p$-wave Fermi gases.

Quantum state tomography (QST) is a central task for quantum information processing, enabling quantum cryptography, computation, and state certification. Traditional QST relies on projective measurements of single- and two-qubit Pauli operators, requiring the system of interest to be isolated from environmental dissipation. In this Letter, we demonstrate that measuring currents and associated transport quantities flowing through a quantum system in an open configuration enables the reconstruction of its quantum state. This result relies on an exact relation between transport quantities and the Krylov subspaces associated with the Lindbladian which encodes the dynamical evolution of an open quantum system. We illustrate this transport approach to QST with the explicit example of a two-qubit system embedded in a two-terminal setup. As a direct consequence of our framework, we are able to provide a transport-based entanglement measure to certify the presence of quantum correlations, expressing the concurrence in terms of current averages and correlation functions only. Our findings are analytical, providing fundamental insights into quantum information processing in open quantum systems. They establish new connections between the fields of mesoscopic physics and quantum information theory.

We conduct the first-ever pulsar polarization array (PPA) analysis to detect the ultralight axionlike dark matter (ALDM) using the polarization data of 22 millisecond pulsars from the third data release of Parkes pulsar timing array. As one of the major dark matter candidates, the ultralight ALDM exhibits a pronounced wave nature on astronomical scales and offers a promising solution to small-scale structure issues within local galaxies. While the linearly polarized pulsar light travels through the ALDM galactic halo, its position angle (PA) can be subject to an oscillation induced by the ALDM Chern-Simons coupling with electromagnetic field. The PPA is thus especially suited for detecting the ultralight ALDM by correlating polarization data across the arrayed pulsars. To accomplish this task, we develop an advanced Bayesian analysis framework that allows us to construct pulsar PA residual time series, model noise contributions properly and search for pulsar cross-correlations. We find that for an ALDM density of ${\rho }_0=0.4\mathrm{GeV}/{\mathrm{cm}}^3$, the Parkes PPA offers the best global limits on the ALDM Chern-Simons coupling, namely $\lesssim {10}^{-13.5}-{10}^{-12.2}{\mathrm{GeV}}^{-1}$, for the mass range of ${10}^{-22}–{10}^{-21}\mathrm{eV}$. The crucial role of pulsar cross-correlation in recognizing the nature of the derived limits is also highlighted.

Combining macroscopic measurements, neutron scattering, and modeling, we identify in the ${\mathrm{GeFe}}_2{\mathrm{O}}_4$ spinel a correlated paramagnetic state resulting from the predominance of third-neighbor antiferromagnetic interactions. These interactions materialize four interlaced families of triangular planes with 120° spins emerging from the underlying pyrochlore lattice. At lower temperatures, a phase transition occurs to a noncoplanar spin structure that is characterized by six propagation vectors. This unusual multi-$q$ order is triggered by the presence of weaker interactions up to the sixth neighbors. The system is remarkably successful in coupling the different triangular planes while maintaining their two-dimensional 120° order. Our Letter highlights the hierarchy of interactions involved in ${\mathrm{GeFe}}_2{\mathrm{O}}_4$, which is singular among spinel compounds since first-neighbor interactions are only a small fraction of the dominant third-neighbor ones.

We show that encrypted cloning of unknown quantum states is possible. Any number of encrypted clones of a qubit can be created through a unitary transformation, and each of the encrypted clones can be decrypted through a unitary transformation. The decryption of an encrypted clone consumes the decryption key; i.e., only one decryption is possible, in agreement with the no-cloning theorem. Encrypted cloning represents a new paradigm that provides a form of redundancy, parallelism, or scalability where direct duplication is forbidden by the no-cloning theorem. For example, a possible application of encrypted cloning is to enable encrypted quantum multicloud storage.

Excitons in monolayer transition metal dichalcogenides ($1L\text{−}\mathrm{TMDs}$) exhibit a Rydberg-like series of bound states, including optically dark levels. Using a three-pulse scheme, we directly track the dynamics of the $2p$ dark exciton in $1L\text{−}{\mathrm{WS}}_2$ through the Autler-Townes splitting of the bright $1s$ state. The splitting, induced by a midinfrared field resonant with the $1s\text{−}2p$ transition, reveals distinct $1s$ and $2p$ responses to photoexcitation. This approach provides new insight into many-body effects and offers a versatile experimental framework to probe driven excitonic dynamics in quantum materials.

We report on the successful trapping of micrometer-sized, multiply-charged helium droplets over periods of several seconds up to a minute—the first observation of trapped charged helium droplets. Within a meter-long multireflection mass spectrometer, the droplets complete thousands of revolutions, opening up new possibilities for precision measurements of these unique systems. Their confinement is limited by collisions with residual gas, which gradually reduce their kinetic energy through evaporation of helium atoms from the droplet and prevent extraction from the trap below a critical value. The rate of energy loss is strongly influenced not only by the residual gas density, but also by the type of species picked up by the droplets. In particular, infrared absorption by water cluster ions inside the droplets enhances energy transfer to the helium matrix, leading to accelerated evaporation of helium atoms.

Spontaneous breaking of time-reversal and spatial-inversion symmetries in solids triggers diverse intriguing phenomena. Although these phenomena have been extensively studied in insulators, similar investigations for metals remain limited. Herein, we report the observation and properties of spontaneous (i.e., zero-magnetic field) nonreciprocal charge transport in the zigzag intermetallic compound ${\mathrm{NdRu}}_2{\mathrm{Al}}_{10}$. This effect is attributed to the antiferromagnetic order, which can be interpreted as a magnetic toroidal dipole order. Our results reveal an excessively large nonreciprocal coefficient for this material, attributed to the strong effective magnetic field generated through $c-f$ exchange interactions. The results also suggest that the nonreciprocal response of this material depends on the spin configurations of the antiferromagnetic domains. Overall, our findings are distinct from those previously reported for field-induced nonreciprocal charge transport and contribute to a comprehensive understanding of cross-correlations in symmetry-broken metals.

Quantum anomalous Hall effect (QAHE) in graphene moiré superlattices has drawn considerable and sustained attention, owing to both fundamental interests of Chern insulators and promising applications in topological electronics. An empirical regularity suggests that QAHE manifests exclusively at odd-electron filling per moiré unit cell, whereas even-filling configurations—particularly at half-filled bands—invariably yield topologically trivial insulators. This dichotomy, originating from quantum states competition, has been the key issue in theoretical investigations of topology and correlation, but its universality remains an open question. Here we demonstrate a violation of this paradigm in rhombohedral heptalayer graphene/hexagonal boron nitride moiré superlattices, where a robust Chern insulator emerges at two-electron filling per moiré unit cell. It wins the competition with a trivial correlated insulator only above a critical displacement field as large as $\sim 1\mathrm{V}/\mathrm{nm}$. The odd Chern number $C=1$ for the filling of 2 is intriguing: theoretical calculation shows that electrons occupy two interaction-renormalized bands with distinct spin-valley flavors, whose charge densities arrange into dual honeycomb and triangular lattices, leading to a total Chern number of 1 and minimized Coulomb repulsion. Our findings broaden the landscape for engineering nontrivial topological states, while providing critical insights into the delicate competition between emergent quantum phases in strongly correlated moiré systems.

The construction of entangling gates with individual addressing capability represents a crucial approach for implementing quantum computation in trapped-ion crystals. Conventional entangling gate schemes typically rely on laser beam wave vectors to couple the ions’ spin and motional degrees of freedom. Here, we experimentally demonstrate an alternative method that employs a polarization gradient field generated by a tightly focused laser beam—an approach theoretically proposed as the Magnus effect for quantum logic gate design [Mazzanti et al., Phys. Rev. Res. 5, 033036 (2023)]. Using this technique, we perform Raman operations on hyperfine qubits encoded in ${{}^{171}\mathrm{Yb}}^{+}$ ions, generating spin-dependent forces along axial motional modes in a linear trap. By utilizing an acousto-optic deflector to create arbitrary spot pairs for individual ion addressing in two-ion (four-ion) chains, we achieve Mølmer-Sørensen gates with Bell-state fidelities exceeding 98.7(1)% [and 97.2(4)%]. Further improvements in numerical aperture (NA) and laser power could reduce gate durations while enhancing fidelity by orders of magnitude. This method is compatible with—and can significantly simplify—optical tweezer gate proposals, where motional mode engineering enables scalable trapped-ion quantum computation. The technique can be readily extended to two-dimensional ion crystals, representing a key advancement toward large-scale trapped-ion quantum processors.

We report the observation of dynamic fringe patterns in the diffuse scattering of extreme ultraviolet light from surfaces, following femtosecond optical excitation. At each point on the detector, the diffuse scattering intensity exhibits oscillations at well-defined frequencies that correspond to surface phonons with wave vectors determined by the scattering geometry, indicating that the optical excitation generates coherent surface phonons propagating in all directions and spanning a wavelength range from 60 to 300 nm. This phenomenon is observed on a variety of samples, including single-layer and multilayer metal films, as well as bulk semiconductors. The measured surface phonon dispersions show good agreement with theoretical calculations. By comparing signal amplitudes from samples with different surface morphologies, we find that the excitation mechanism is linked to the natural surface roughness of the samples. However, the signal is still detectable on extremely smooth surfaces with subnanometer roughness. Our findings demonstrate a simple and effective method for optically exciting coherent surface phonons with nanoscale wavelengths on a wide range of solid samples and establish a foundation for surface phonon spectroscopy in a wave vector range well beyond the limit of conventional surface Brillouin scattering.

We establish a sharp quantum advantage in determining the parity (even-odd) of an unknown permutation applied to any number $n\ge 3$ of particles. Classically, this is impossible with fewer than $n$ labels, being that the success is limited to random guessing. Quantum mechanics does it with certainty with as few as $\lceil \sqrt{n}\rceil$ distinguishable states per particle, thanks to entanglement. Below this threshold, not even quantum mechanics helps: both classical and quantum success are limited to random guessing. For small $n$, we provide explicit expressions for states that ensure perfect parity identification. We also assess the minimum entanglement these states need to carry, finding it to be close to maximal, and even maximal in some cases. The task requires no oracles or contrived setups and provides a simple, rigorous example of genuine quantum advantage.

Optical atomic clocks play a crucial role in fundamental physics, relativistic geodesy, and the future redefinition of the Systeme International second. Standard operation relies on cyclic interrogation sequences, which alternate between atomic interrogation and dead time used for state preparation and readout. This approach introduces the Dick effect, where laser frequency noise aliases onto the atomic transition frequency. Although reducing laser noise improves clock stability, the Dick effect remains a key limitation. In this Letter, we demonstrate a zero-dead-time optical clock based on two interleaved ensembles of cold ${}^{87}\mathrm{Sr}$ atoms. Our system significantly suppresses this noise and achieves a fractional frequency instability at the ${10}^{-19}$ level between 10 000 and 20 000 s over repeated measurements, with a best value of $2.9\times {10}^{-19}$ at $\tau =20000\mathrm{s}$. The estimated long-term stability based on the combined data of these measurements reaches $2.5\times {10}^{-19}$ at 1 day. These results represent a more than ninefold improvement over a conventional single-ensemble clock, highlighting its potential for next-generation timekeeping applications.

We report fast atom diffraction through single-layer graphene using hydrogen atoms at kinetic energies from 150 to 1200 eV. High-resolution images reveal overlapping hexagonal patterns from coexisting monocrystalline domains. Time-of-flight tagging confirms negligible energy loss, making the method suitable for matter-wave interferometry. The diffraction is well described by the eikonal approximation, with accurate modeling requiring the full 3D interaction potential from density functional theory. Simpler models fail to reproduce the data, highlighting the exceptional sensitivity of diffraction patterns to atom-surface interactions and their potential for spectroscopic applications.

We report the experimental observation of discrete bright matter-wave solitons with attractive interaction in an optical lattice. Using an accordion lattice with adjustable spacing, we prepare a Bose-Einstein condensate of cesium atoms across a defined number of lattice sites. By quenching the interaction strength and the trapping potential, we generate both single-site and multisite solitons. Our results reveal the existence and characteristics of these solitons across a range of lattice depths and spacings. We identify stable regions of the solitons based on interaction strength and lattice properties, and compare these findings with theoretical predictions. The experimental results qualitatively agree with a Gaussian variational model and match quantitatively with numerical simulations of the three-dimensional Gross-Pitaevskii equation extended with a quintic term to account for the loss of atoms. Our results provide insights into the quench dynamics and collapse mechanisms, paving the way for further studies of transport and dynamical properties of matter-wave solitons in lattices.