All-photonic quantum repeaters are essential for establishing long-range quantum entanglement. Within repeater nodes, reliably performing entanglement swapping is a key component of scalable quantum communication. To tackle the challenge of probabilistic Bell state measurement in linear optics, which often leads to information loss, various approaches have been proposed to ensure the loss tolerance of distributing a single ebit. We have generalized previous work regarding repeater graph states with elaborate connectivity, enabling the efficient establishment of exploitable ebits at a finite rate with high probability. We demonstrate that our new scheme significantly outperforms the previous work with much flexibility and discuss the generation overhead of such resource states. These findings offer new insights into the scalability and reliability of loss-tolerant quantum networks.

We propose an entropy function for ${\mathrm{AdS}}_4$ BPS black holes in M theory with general magnetic charges, resolving in particular a long-standing puzzle about baryonic charges. The entropy function is constructed from a gravitational block defined solely in terms of topological data of the internal manifold. We show that the entropy of twisted black holes can always be reformulated as an $\mathcal{I}$-extremization problem—even in cases where existing large-$N$ field theory computations fail to provide an answer. Furthermore, we correctly reproduce the entropy for a class of known black holes with purely baryonic magnetic charges. Our results offer both a conjecture for the general gravitational block for ${\mathrm{AdS}}_4$ black holes in M theory and a prediction for the large-$N$ limit of several partition functions whose saddle points have yet to be found.

Using $(2712.4\pm 14.3)\times {10}^6$ $\psi (3686)$ events collected with the BESIII detector at BEPCII, a partial wave analysis of the decay $\psi (3686)\to \varphi \eta {\eta }^{\prime }$ is performed with the covariant tensor approach. In addition to the established states $h_1(1900$) and $\varphi (2170)$, an axial-vector state with a mass near $2.3\mathrm{GeV}/c^2$ is observed for the first time. Its mass and width are measured to be $2316\pm 9_{\mathrm{stat}}\pm 30_{\mathrm{syst}}\mathrm{MeV}/c^2$ and $89\pm 15_{\mathrm{stat}}\pm 26_{\mathrm{syst}}\mathrm{MeV}$, respectively. The product branching fractions of $\mathcal{B}[\psi (3686)\to X(2300){\eta }^{\prime }]\mathcal{B}[X(2300)\to \varphi \eta ]$ and $\mathcal{B}[\psi (3686)\to X(2300)\eta ]\mathcal{B}[X(2300)\to \varphi {\eta }^{\prime }]$ are determined to be $(4.8\pm {1.3}_{\mathrm{stat}}\pm {0.7}_{\mathrm{syst}})\times {10}^{-6}$ and $(2.2\pm {0.7}_{\mathrm{stat}}\pm {0.7}_{\mathrm{syst}})\times {10}^{-6}$, respectively. The branching fraction $\mathcal{B}[\psi (3686)\to \varphi \eta {\eta }^{\prime }]$ is measured for the first time to be ($3.14\pm 0.17_{\mathrm{stat}}\pm 0.24_{\mathrm{syst}})\times {10}^{-5}$. The first uncertainties are statistical and the second are systematic.

The parity-violating asymmetry, including leading-order QED corrections to the Coulomb potential, is calculated nonperturbatively by solving the Dirac equation. At GeV collision energies and forward scattering angles, QED effects enhance the asymmetry by approximately 5% for the recently measured nuclei ${}^{27}\mathrm{Al}$, ${}^{48}\mathrm{Ca}$, and ${}^{208}\mathrm{Pb}$. The corrections result in a shift of the estimated neutron radius, leading to an increase in the inferred neutron skin thicknesses of these nuclei and, thus, to the pressure neutrons feel around nuclear saturation density.

We propose a general method embedded in the ab initio nuclear framework to reconstruct linear response functions and calculate sum rules. Within our approach, based on the Gaussian integral transform, we consistently treat the ground state and the excited spectrum. Crucially, the method allows for a robust uncertainty estimation of the spectral reconstruction. We employ it to obtain the spin response in neutron matter. Our calculations are performed using state-of-the-art many-body coupled-cluster method and Hamiltonians derived in the chiral effective field theory, emphasizing the analysis of finite-size effects. Our findings reveal that the spin response exhibits a strong dependence on both nuclear interactions and many-body wave functions, offering a new avenue for exploring nuclear correlations and dynamics in infinite systems. This work serves as a stepping stone toward further studies of neutrino interactions in astrophysical environments from first principles.

An intercombination transition in Yb enables a novel approach for rapidly imaging magnetic field variations with excellent spatial and temporal resolution and accuracy. This quantum imaging magnetometer reveals “dark stripes” that are contours of constant magnetic field visible by eye or capturable by standard cameras. These dark lines result from a combination of Autler-Townes splitting and the spatial Hanle effect in the ${}^1{\mathrm{S}}_0\text{−}{}^3{\mathrm{P}}_1$ transition of Yb when driven by multiple strong coherent laser fields (carrier and AM/FM modulation sidebands of a single-mode 556 nm laser). We show good agreement between experimental data and our theoretical model for the closed, 4-level Zeeman shifted V system and demonstrate scalar and vector magnetic field measurements at video frame rates over spatial dimensions of 5 cm with 0.1 mm resolution. Additionally, the ${}^1{\mathrm{S}}_0\text{−}{}^3{\mathrm{P}}_1$ transition allows for $\sim \mathrm{\mu }\mathrm{s}$ response time and a large dynamic range (from microtesla to many tesla).

We present high precision measurements of the radiative heat transfer of a glass microsphere immersed in a thermal bath in vacuum facing three different planar substrates (${\mathrm{SiO}}_2$, SiC, and Au), which exhibit very different optical behaviors in the infrared region. Using a thermoresistive probe on a cantilever, we show the nonmonotonic behavior of the radiative flux between the microsphere and its environment when the microsphere is brought closer to the substrate in the far-field to near-field transition regime. We demonstrate that this unexpected behavior is related to the singularities of dressed emission mechanisms in this three-body system sphere-substrate bath with respect to the separation distance.

We resolve the dewetting dynamics of water films on partially wetting surfaces at the microscopic scale and highlight its distinctions from liquid wetting. Fast dewetting occurring at the millisecond scale is dominated by capillary and inertial forces, obeying a power law with a wettability-independent exponent, which is different from the capillary-inertial dynamic wetting. Molecular-level inspections of moving contact lines further reveal that liquid molecules retract from solid surfaces through a rolling motion, whereas dynamic wetting proceeds mainly with the sliding motion. These distinct hydrodynamic behaviors and molecular kinetics explicitly suggest that dynamic dewetting is not simply the reverse of dynamic wetting, which has significant implications for interfacial fluid physics.

Many theories predict a quartic increase of the acoustic damping at sub-THz frequencies in glassy media, related to the excess vibrational modes known as the boson peak anomaly. Here by introducing phase-sensitive acoustic spectroscopy techniques with a THz bandwidth, we investigate the acoustic properties of vitreous silica at 15 and 300 K in the crucial but unexplored sub-THz gap region below the boson peak. Our results indicate a negative dispersion below the THz range and the onset of an athermal quartic frequency scaling acoustic attenuation term, which appears above all other thermal losses.

We investigate the hydrodynamic regime in metals with momentum-conserving electron-electron scattering. The conservation of momentum results in well-defined dynamics whose effects we investigate via the relevant continuity equations. We find anomalous contributions to the charge and heat transport currents arising from gradients of the velocity field in a semiclassical treatment with a Berry curvature. These contributions are nonvanishing for systems lacking inversion symmetry, and the corresponding transport coefficients do not obey the standard Onsager reciprocity relations. Instead, we show that the response coefficients relating the currents to the stress tensor obey independent reciprocity relations with the stress tensor and thus exhibit cross-tensor effects of charge and heat transport with the momentum transport. The Berry curvature contribution to the stress magnetization tensor is also derived.

In the search of fractional quantum anomalous Hall (FQAH) effect, the conventional wisdom is to start from a flat Chern band isolated from the rest of the Hilbert space by band gaps, so that many-body interaction can be projected to a landscape that mimics a Landau level. Singular flat bands (SFB), which share protected touching points with other dispersive bands, represent another type of flat landscapes differing from Landau levels and Chern bands in topological and geometric properties. Here we report the finding of FQAH phases in a SFB, which emerges in the bipartite limit of the nearest-neighbor tight-binding model of twisted bilayer ${\mathrm{MoTe}}_2$. At $1/3$ and $2/3$ filling of the SFB, FQAH effects are demonstrated using density matrix renormalization group calculations with all bands, as well as exact diagonalization calculations with the two touching bands. Gapping the band touching can turn the SFB into a nearly flat Chern band, but counterintuitively this suppresses the FQAH effect, as the gap opening introduces strong inhomogeneity to the quantum geometry. An optical scheme to realize such SFB for cold atoms is provided. Our findings uncover a new arena for the exploration of fractional quantum Hall physics beyond the Landau level and Chern insulator paradigms.

The diversity of diffusive systems exhibiting long-range correlations characterized by a stochastically varying Hurst exponent calls for a generic multifractional model. We present a simple, analytically tractable model which fills the gap between mathematical formulations of multifractional Brownian motion and empirical studies. In our model, called telegraphic multifractional Brownian motion, the Hurst exponent is modeled by a smoothed telegraph process which results in a stationary beta distribution of exponents as observed in biological experiments. We also provide a methodology to identify our model in experimental data and present concrete examples from biology, climate, and finance to demonstrate the efficacy of our approach.

Common envelope evolution—where a star is engulfed by a companion—is a critical but poorly understood step in, e.g., the formation pathways for gravitational-wave sources. However, it has been extremely challenging to identify observable signatures of such systems. We show that for systems involving a neutron star, the hypothesized super-Eddington accretion onto the neutron star produces MeV-range, months-long neutrino signals within reach of present and planned detectors. While there are substantial uncertainties on the rate of such events ($0.01–1/\text{century}$ in the Milky Way) and the neutrino luminosity (which may be less than the accretion power), this signal can only be found if dedicated new analyses are developed. If detected, the neutrino signal would probe super-Eddington accretion, leading to significant new insights into the astrophysics of common envelope evolution.

The first test of lepton flavor universality between muons and electrons using $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$ ($\ell =e$, $\mu$) decays is presented. The measurement is performed with data from proton-proton collisions collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$. The ratio of branching fractions between $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$ decays is measured in the dilepton invariant-mass-squared range $1.1<q^2<7.0{\mathrm{GeV}}^2/c^4$ and is found to be $R_{K\pi \pi }^{-1}=1.31_{-0.17}^{+0.18}(\mathrm{stat}){}_{-0.09}^{+0.12}(\mathrm{syst})$, in agreement with the standard model prediction. The first observation of the $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ decay is also reported.

High-order virtual excitations play an important role in microscopic models of nuclear reactions at intermediate energies. However, the factorial growth of their complexity has prevented their consistent inclusion in ab initio many-body calculations. For infinite systems at finite temperature, such drawbacks can be overcome using diagrammatic Monte Carlo techniques to resum entire series of Feynman diagrams. We present a diagrammatic Monte Carlo algorithm that can be applied to self-bound systems with discrete energy levels at zero temperature, and demonstrate its potential for the Richardson model of nuclear pairing. We show that sampling the topological space of diagrams allows the inclusion of high-order excitations that are neglected in state-of-the-art approximations used in nuclear physics and quantum chemistry. We propose that sampling the diagrammatic space can overcome the long-standing gap between our microscopic understanding of structure and reactions in nuclear physics.

We describe an experiment demonstrating the generation of three independent square-ladder continuous-variable cluster states with up to 94 qumodes of a microwave frequency comb. This entanglement structure at a large scale is realized by injecting vacuum fluctuations into a Josephson Parametric Amplifier pumped by three coherent signals around twice its resonance frequency, each having a particular well-defined phase relation. We reach up to 1.4 dB of squeezing of the nullifier that verifies the cluster state on the square ladder graph. Our results are consistent with a more familiar measure of two-mode squeezing, where we find up to 5.42 dB for one pump, and up to 1 dB for three pumps.

In the hydrodynamic theory, the nonequilibrium dynamics of a many-body system is approximated, at large scales of space and time, by irreversible relaxation to local entropy maximization. This results in a convective equation corrected by viscous or diffusive terms in a gradient expansion, such as the Navier-Stokes equations. Diffusive terms are evaluated using the Kubo formula, and possibly arising from an emergent noise due to discarded microscopic degrees of freedom. In one dimension of space, diffusive scaling is often broken as noise leads to superdiffusion. But in linearly degenerate hydrodynamics, such as that of integrable models, diffusive behaviors are observed, and it has long been thought that the standard diffusive picture remains valid. In this Letter, we show that in such systems, the Navier-Stokes equation breaks down beyond linear response. We demonstrate that diffusive-order corrections do not take the form of a gradient expansion. Instead, they are completely determined by ballistic transport of initial-state fluctuations, and obtained from the nonlocal two-point correlations recently predicted by the ballistic macroscopic fluctuation theory; the resulting hydrodynamic equations are reversible. To do so, we establish a regularized fluctuation theory, putting on a firm basis the recent idea that ballistic transport of initial-state fluctuations determines fluctuations and correlations beyond the Euler scale. This extends the idea of “diffusion from convection” previously developed to explain the Kubo formula in integrable systems to generic nonequilibrium settings.