Optical sensing schemes based on two-photon interference offer a powerful platform for precision metrology, but are usually limited by a trade-off between dynamic range and measurement precision. Here, we overcome this limitation by resolving the frequency of two photons impinging on a beam splitter and combining these measurements with a new estimation strategy. This increases the usable dynamic range by up to a factor of 20 compared with conventional frequency nonresolved schemes. We implement the method with independent photon pair sources and characterize its performance in the presence of finite-resolution frequency-resolved detectors, which approach the quantum limit in the lossless regime. Our approach enables scan-free, nanometer resolution depth sensing over millimeter scale distances, with potential applications in biological and nanomaterial imaging.

We present gokunemu, a ten-dimensional neural network emulator for the nonlinear matter power spectrum, designed to support next-generation cosmological analyses. Built on the Goku $N$-body simulation suite and the t2n-muse emulation framework, gokunemu predicts the matter power spectrum with $\sim 0.5\%$ average accuracy for redshifts $0\le z\le 3$ and scales $0.006\le k/(h{\mathrm{Mpc}}^{-1})\le 10$. The emulator models a 10D parameter space that extends beyond $\mathrm{\Lambda }$-cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) to include dynamical dark energy (characterized by $w_0$ and $w_a$), massive neutrinos ($\sum m_{\nu }$), the effective number of neutrinos ($N_{\mathrm{eff}}$), and running of the primordial spectral index (${\alpha }_{\mathrm{s}}$). Its broad parameter coverage, particularly for the extensions, makes it the only matter power spectrum emulator encompassing the range of dynamical dark energy models preferred by recent DESI constraints. In addition, it requires only $\sim 2$ milliseconds to predict a single cosmology on a laptop, orders of magnitude faster than existing emulators. These features make gokunemu a uniquely powerful tool for interpreting observational data from upcoming surveys such as LSST, Euclid, the Roman Space Telescope, and CSST.

Gravity in nonlinear and dynamical regimes underpins spectacular astrophysical phenomena and observable consequences, from the early Universe to black hole collisions. In these extreme environments, “inverse energy cascades”—mediated by nonlinear interactions—may help explain the near scale invariance of cosmic structure and the simplicity of gravitational waves from binary black hole mergers. Yet the presence, characteristics, and generality of such interactions in full general relativity remain largely unexplored. Here we show that two types of nonlinear interactions—a four-mode and a three-mode interaction—emerge in the fully nonlinear regime and can indeed channel inverse energy cascades by inducing resonant and antidamping (transient) nonlinear instabilities. We further demonstrate a “laminar” to “turbulent” transition for the largest-possible angular structure in general relativity, whereas finer structures remain persistently turbulent. Our results reveal the impact and generality of these nonlinear interactions (instabilities), which can be key to understanding observations ranging from cosmological to kilometer scales. We anticipate that our Letter will shed new light on nonlinear gravitational phenomena and their consequences, such as constructing gravitational-wave templates and testing general relativity in the most extreme regime. Moreover, our Letter is a starting point for addressing nonlinear gravitational interactions using ideas and methods inspired by fluid dynamics.

We construct Hamiltonian models on a $3+1\mathrm{D}$ cubic lattice for a single Weyl fermion and for a single Weyl doublet protected by exact (as opposed to emergent) chiral symmetries. In the former, we find a not-on-site, noncompact chiral symmetry which can be viewed as a Hamiltonian analog of the Ginsparg-Wilson symmetry in Euclidean lattice models of Weyl fermions. In the latter, we combine an on-site U(1) symmetry with a not-on-site U(1) symmetry, which together generate the SU(2) flavor symmetry of the doublet at low energies, while in the UV they generate an algebra known in integrability as the Onsager algebra. This latter model is in fact the celebrated magnetic Weyl semimetal, which is known to have a chiral anomaly from the action of U(1) and crystalline translation. This anomaly gives rise to an anomalous Hall response; however, when reinterpreted in our language, the model has two exact U(1) symmetries that give rise to the global SU(2) anomaly, which protects the gaplessness even when crystalline translations are broken. We also construct an exact symmetry-protected single Dirac cone in $2+1\mathrm{D}$ with the $\mathrm{U}(1)⋊T$ parity anomaly. Our constructions evade both old and recently proven no-go theorems by using not-on-siteness in a crucial way, showing our results are sharp.

We propose a new particle-trajectory detector composed of Josephson junctions, named the superconducting cloud chamber. By measuring the quantum phase difference, this device can detect charged particles with extremely low kinetic energy, providing a new method for detecting slow-moving particles. It can also be utilized to detect millicharged dark matter particles thermalized with the Earth’s environment within the mass range of ${10}^3\sim {10}^{10}\mathrm{GeV}$.

Isotope shift metrology in the deep-UV region has been performed for all bosonic isotopes of mercury with a zero nuclear spin, using the technique of frequency-comb referenced, wavelength-modulated, saturated absorption spectroscopy. The absolute center frequencies of the $6{\mathrm{s}}^2{{}^1\mathrm{S}}_0\to 6\mathrm{s}6\mathrm{p}{{}^3\mathrm{P}}_1$ transition have been measured with precision in the range of $2.5–5.9{10}^{-12}$ in temperature-stabilized Hg vapor samples with natural abundances. Frequency shifts in four isotope pairs have been determined with unprecedented accuracy, the global uncertainty being improved by a factor greater than 20 with respect to the best experimental data of the past literature. Our dataset, when combined with previous measurements on the 6s6p ${{}^3\mathrm{P}}_2\to 6\mathrm{s}7\mathrm{s}$ ${{}^3\mathrm{S}}_1$ transition at 546 nm, allows us to build a King plot that reveals a nonlinearity with a statistical significance of $4.6\sigma$.

We demonstrate a method for controlling the outcome of an ultracold chemical few-body reaction by redirecting a tunable fraction of reaction flux from one selected product channel to another one. In the reaction, three ultracold atoms collide to form a diatomic molecule. This product molecule can be produced in various internal states, characterizing the different product channels of the reaction. Our scheme relies on the coupling between two such product channels at an avoided molecular energy level crossing in the presence of an external magnetic field. The degree of coupling can be set by the magnetic field strength and allows for a widely tunable flux control between the two channels. This scheme is quite general and also holds great promise for a large variety of chemical processes with diverse species, since molecular energy level crossings are ubiquitous in molecular systems and are often easily accessible by standard laboratory equipment.

Muon spin rotation ($\mu \mathrm{SR}$) measurements of internal magnetic field shifts, known as the muon Knight shift, are used for determining pairing symmetries in superconductors. While this technique has been especially effective for $f$-electron-based heavy-fermion superconductors, it remains challenging in $d$-electron-based superconductors such as ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$, where the Knight shift is intrinsically small. Here, we report high-precision muon Knight shift measurements of superconducting ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$. We observe that using multiple pieces of crystals, a common practice in $\mu \mathrm{SR}$ measurements, induces a substantial paramagnetic shift below the superconducting transition temperature, $T_{\mathrm{c}}$, when a weak magnetic field is applied. We attribute such an unresolved paramagnetic shift to stray fields generated by neighboring diamagnetic crystals. To avoid this, one piece of crystal was used in this Letter. We experimentally determine the muon Knight shift of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ in the normal state to be $-116\pm 7\mathrm{ppm}$. By combining the observed muon Knight shift with independently determined bulk magnetization data from the same crystal used in $\mu \mathrm{SR}$ and carefully separating various contributions to the shift, we confirm a significant reduction in the spin Knight shift below $T_{\mathrm{c}}$, consistent with spin-singlet-like pairing. This result constitutes the precise muon Knight shift measurement in a $d$-electron-based superconductor. Our results highlight the potential of $\mu \mathrm{SR}$ as a powerful complementary technique to the established method of nuclear magnetic resonance for probing the spin susceptibility in superconductors.

This Letter inspects the thermally activated transfer of solute particles across the interface between two interstitial solid solution phases that equilibrate internally by fast diffusion on conserved arrays of sites. When each phase is considered as an ergodic ensemble of particles, statistical mechanics predicts the occupancy of the transition states at equilibrium to depend on the barrier energy and on the chemical potentials and vacancy fractions in each of the phases. A rate law for the nonequilibrium interfacial transfer, based on a constant transition probability between activated states, naturally satisfies the principle of detailed balance. Contrary to Butler-Volmer-type laws, values of the particle chemical potentials enter explicitly rather than through their differences. This, along with the dependency on the vacancy fractions, implies here an exchange flux density that depends explicitly on the compositions at equilibrium. The results can explain experimental observations of a drastic slowdown in the charging of metal hydrides near phase transformations or miscibility-gap critical points.

We demonstrate that there exists frequency-domain Berry curvature in the wave function of photons in dispersive optical systems. This property arises from the frequency dispersion of its dielectric function, which makes Maxwell equations a nonstandard eigenvalue equation, with the eigenvalue (frequency) appearing inside the operator itself. We study this new Berry curvature effect on time refraction of magnetoplasmon-polariton as an example. It can induce deflection in the trajectory of a photon and make the ray swing.

We show that intervalley coupling can be induced in twisted bilayer graphene (TBG) by aligning the bottom graphene layer with either of two types of commensurate insulating triangular Bravais lattice substrate. The intervalley coupling folds the $\pm K$ valleys of TBG to the $\mathrm{\Gamma }$-point and hybridizes the original TBG flat bands into a four-band model equivalent to the $p_x\text{−}{p}_y$ orbital honeycomb lattice model, in which the second conduction and valence bands have quadratic band touchings and can become flat due to geometric frustration. The spin-orbit coupling from the substrate opens gaps between the bands, yielding topological bands with spin Chern numbers $\mathcal{C}$ up to $\pm 4$. For realistic substrate potential strengths, the minimal bandwidths of the hybridized flat bands are still achieved around the TBG magic angle ${\theta }_M=1.05°$, and their quantum metrics are nearly ideal. We identify two candidate substrate materials ${\mathrm{Sb}}_2{\mathrm{Te}}_3$ and ${\mathrm{GeSb}}_2{\mathrm{Te}}_4$, which nearly perfectly realize the commensurate lattice constant ratio of $\sqrt{3}$ with graphene. These systems provide a promising platform for exploring strongly correlated topological states driven by geometric frustration.

The topology of an insulator can be defined even when all eigenstates of the system are localized—an extreme case of Anderson insulators that we call ultralocalized. We derive the classification of such ultralocalized insulators in all symmetry classes and dimensions. We clarify their bulk-boundary correspondence and show that ultralocalized systems are in many instances phases of matter not described by the known classification of topological insulators and superconductors. As a consequence, we clarify which conventional topological phases are Wannierizable, and which topological phases cannot exist without delocalized states.

We succeeded in fabricating an ideal, bulk-insulating ferromagnetic topological crystalline insulator by doping Mn to SnTe films grown on ${\mathrm{Bi}}_2{\mathrm{Te}}_3$. The cancellation of the polarity of SnTe surface and electron doping due to Bi and Mn leads to an ideal case where only the electron and holes of topological surface Dirac carriers exist at the Fermi level in different region of the surface Brillouin zone and their competition results in a nonlinear Hall effect. Ferromagnetism has been confirmed at 3.5 K through the detection of the anomalous Hall effect. These properties can potentially serve to realize and manipulate the high-Chern number quantum anomalous Hall effect.

We consider overdamped physical systems evolving under a feedback-controlled fluctuating potential and in contact with a thermal bath at temperature $T$. A Markovian description of the dynamics, which keeps only the last value of the control action, is advantageous—both from the theoretical and the practical side—for the entropy balance. Novel second-law equalities and bounds for the extractable work are obtained, the latter being both tighter and easier to evaluate than those in the literature based on the whole chain of controller actions. The Markovian framework also allows us to prove that the bound for the extractable work that incorporates the unavailable information is saturated in a wide class of physical systems, for error-free measurements. These results are illustrated in model systems. For imperfect measurements, there appears an interval of measurement uncertainty, including the point at which work ceases to be extracted, where the new Markovian bound is tighter than the unavailable information bound.

We measured negative grain-boundary triple line tension within bulk hard-sphere colloidal polycrystals. Compared to the grain boundaries, the tension is predominantly distributed in the grain lattices. The negative tension drives finite premelting at triple junctions and leads to a marginally denser lattice nearby.

The interplay between protein folding and native dynamics remains a central question in biophysics. Analyzing an extensive set of AlphaFold-predicted structures, we uncover a robust relationship between folding topology (contact order) and native dynamics (fluctuation entropy), showing that long-range contacts that slow folding also restrict conformational flexibility across protein sizes and taxonomic groups. Scaling analysis reveals that this relationship, together with its chain-length dependence, is consistent with power-law–like trends, reflecting common organizing constraints of protein architecture. Across species, increasing organismal complexity is associated with proteome-wide shifts toward lower contact order and higher fluctuation entropy. Together, evidence from folding, stability, and functional dynamics converges on unifying constraints, revealing an intrinsic physical organizing principle captured by AI models.

Catalysis refers to the possibility of enabling otherwise inaccessible quantum state transitions by supplying an auxiliary system, provided that the auxiliary is returned to its initial state at the end of the protocol. We show that previous studies on catalysis are largely impractical, because even small errors in the system’s initial state can irreversibly degrade the catalyst. To overcome this limitation, we introduce “robust catalytic transformations” and explore the fundamental extent of their capabilities. We demonstrate that robust catalysis is closely tied to the property of resource broadcasting. In particular, in completely resource nongenerating theories, robust catalysis is possible if and only if resource broadcasting is possible. We develop a no-go theorem under a set of general axioms, demonstrating that robust catalysis is unattainable for a broad class of quantum resource theories. However, surprisingly, we also identify thermodynamical scenarios where maximal robust catalytic advantage can be achieved. Our approach clarifies the practical prospects of catalytic advantage for a wide range of quantum resources, including entanglement, coherence, thermodynamics, nonstabilizerness, and imaginarity.

Constructing a quantum memory node with the ability of long-distance atom-photon distribution is the essential task for future quantum networks, enabling distributed quantum computing, quantum cryptography, and remote sensing. Here we report the demonstration of a quantum-network node with a simple cavity-free cold atomic ensemble. This node gives an initial retrieval efficiency of approximately 55% and memory lifetime of $160\mathrm{\mu }\mathrm{s}$ for atomic qubits. With the aid of a high-efficiency and polarization-independent quantum frequency conversion (QFC) module, the generated entangled photon in the node at 780-nm wavelength is converted to telecom S band at 1522 nm, enabling atom-photon distribution over long distance. We observe an entanglement fidelity between the atoms and telecom photon exceeding 80% after photon transmission over 20-km fiber with an end excitation probability of 0.2% and repetition of 1.7 kHz, the remaining infidelity being dominated by atomic decoherence. The low-noise QFC with an external efficiency up to 48.5% gives a signal-to-noise ratio of 6.9 for transmitted photons with fiber length up to 100 km, laying the cornerstone for entanglement distribution at a hundred-km level. This result provides a new platform toward the realization of a long-distance quantum network.