The thinning of liquid sheets and the resulting capillary waves due to surfactant deposition are relevant to understanding how bubbles burst, with implications for the environment, health, and industry. Here, a similarity solution is obtained, which describes the sheet thinning and capillary waves. The final rupture mechanism of a bubble is explored, suggesting that insoluble surfactant deposition alone does not cause finite-time rupture; instead, sufficient thinning may allow other physical mechanisms to do so. Comparisons to an existing experiment and suggestions for measurements are given.

We study linear scaling relations in electron-phonon superconductors. By combining numerical and analytical techniques, we find linear Homes scaling relations between the zero-temperature superfluid density and the normal-state dc conductivity. This phenomenon arises via either a large impurity scattering rate or inelastic scattering of electrons and Einstein phonons at large electron-phonon coupling. Thus, our Letter shows that Homes scaling is more universal than either cuprate or BCS-like physics and is, instead, a fundamental result in a wide class of superconductors.

High-entropy materials shift the traditional materials discovery paradigm to one that leverages disorder, enabling access to unique chemistries unreachable through enthalpy alone. We present a self-consistent approach integrating computation and experiment to understand and explore single-phase rocksalt high-entropy oxides. By leveraging a machine-learning interatomic potential, we rapidly and accurately map high-entropy composition space using our two descriptors: bond length distribution and mixing enthalpy. The single-phase stabilities for all experimentally stabilized rocksalt compositions are correctly resolved, with dozens more compositions awaiting discovery.

It is still an open question if magnetoelectric coupling occurs at the atomic scale in multiferroic ${\mathrm{BiFeO}}_3$. Nuclear solid-state techniques monitor local fields at the atomic scale. Using such an approach, we show that, contrary to our own expectation, ferroelectric and magnetic ordering in bismuth ferrite (${\mathrm{BiFeO}}_3$ or BFO) decouple at the unit-cell level. Time differential perturbed angular correlation (TDPAC) data at temperatures below, close, and above the magnetic Néel temperature show that the coupling of the ferroelectric order to magnetization is completely absent at the bismuth site. It is common understanding that the antiferromagnetic order and the cycloidal ordering due to the Dzyaloshinskii-Moriya interaction generate a net zero magnetization of the sample canceling out any magnetoelectric effect at the macroscopic level. Our previous data show that a very large coupling of magnetic moment and electrical distortions arises on the magnetic sublattice (Fe site). The oxygen octahedra around the iron site experience a large tilt due to the onset of magnetic ordering. Nevertheless, the Bi-containing complementary sublattice carrying the largest part of ferroelectric order is practically unaffected by this large structural change in its direct vicinity. The magnetoelectric coupling thus vanishes already at the unit cell level. These experimental results agree well with an ab initio density functional theory (DFT) calculation.

Autferroics, recently proposed as a sister branch of multiferroics, exhibit strong intrinsic magnetoelectricity, but ferroelectricity and magnetism are mutually exclusive rather than coexisting. Here, a general model is considered based on the Landau theory, to clarify the distinction between multiferroics and autferroics by qualitative change-rotation in a Landau free energy landscape and in particular phase mapping. The ${\mathrm{TiGeSe}}_3$ exemplifies a factual material, whose first-principles computed Landau coefficients predict its autferroicity. Our investigation paves the way for an alternative avenue in the pursuit of intrinsically strong magnetoelectrics.

Using environmental scanning transmission electron microscopy and a global optimization algorithm, we unraveled the preoxidation dispersion and direct dispersion mechanisms in ${\mathrm{Pd}\text{−}\mathrm{CeO}}_2(100)$ systems, mediated by the behaviors of highly dispersed Pd species. At lower temperatures, Pd nanoparticles first undergo oxidation, followed by the dispersion of PdO nanoparticles. In contrast, at higher temperatures, Pd nanoparticles directly convert into highly distributed cationic Pd species. These distinct dispersion mechanisms are driven by the thermodynamic and kinetic differences of environment-dependent Pd1-2O and Pd1-4O species, providing a fundamental basis for precisely controlling catalyst dispersion states.

The stretching response of polymer chains fundamentally determines the mechanical properties of polymer networks. In this Letter, we develop a statistical mechanics model that incorporates both bond stretching and bond angle deformation, enabling accurate predictions of chain behavior up to large forces. We further propose a semianalytical deformable freely rotating chain (dFRC) model, which represents the chain as a freely rotating chain with effective bond stretch and bond angle that depend on the chain stretch. Using physical parameters without fitting, both the statistical and dFRC models achieve excellent agreement with experimental data for carbon chains across all force regimes. Additionally, the dFRC model provides a direct estimate of the bond force, which is important to predict chain scission. By capturing key bond deformations while remaining computationally efficient, our work lays the foundation for future modeling of polymer network elasticity and failure.

Quantum decoherence is the effect that bridges quantum physics to well-understood classical physics. As such, it plays a crucial role in understanding the mysterious nature of quantum physics. Quantum decoherence is also a source of quantum noise that has to be well under control in quantum computing and in various experiments based on quantum technologies. Here we point out that quantum decoherence can be captured by complex saddle points in the Feynman path integral in much the same way as quantum tunneling can be captured by instantons. In particular, we present some first-principle calculations in the Caldeira–Leggett model, which reproduce the predicted scaling behavior of quantum decoherence with respect to the parameters of the environment such as the temperature and the coupling to the system of interest. We also discuss how to extend our approach to general models by Monte Carlo calculations using a recently developed method to overcome the sign problem.

The recent breakthroughs regarding the detection of compact binary mergers via gravitational waves opened up a new window to the Universe. Gravitational-wave models have been essential to this success since they are necessary to infer the properties of the compact binary system from the observational data. Next-generation detectors, such as the Einstein Telescope, will allow for more observations of binary neutron star mergers with higher precision, making accurate waveform models crucial in describing these systems. In this Letter, we propose a novel approach for constructing phenomenological waveform models informed by observational data. Using mock data representing a one-year operation of the Einstein telescope as our baseline, we demonstrate how the results improve as more events are included in the calibration. This method offers a new and complementary approach for developing sophisticated gravitational-wave models compared to classical techniques that employ analytical computations and numerical-relativity simulations. Improved waveform models will then yield more accurate parameter estimation.

The type IIB matrix model is conjectured to describe superstring theory nonperturbatively in terms of ten $N\times N$ bosonic traceless Hermitian matrices $A_{\mu }$ ($\mu =0,\dots ,9$), whose eigenvalues correspond to ($9+1$)-dimensional space-time. Quite often, this model has been investigated in its Euclidean version, which is well defined although the $\mathrm{SO}(9,1)$ Lorentz symmetry of the original model is replaced by the $\mathrm{SO}(10)$ rotational symmetry. Recently, a well-defined model respecting the Lorentz symmetry has been proposed by “gauge-fixing” the Lorentz symmetry nonperturbatively using the Faddeev-Popov procedure. Here we investigate the two models by Monte Carlo simulations overcoming the severe sign problem by the Lefschetz thimble method, in the case of matrix size $N=2$ omitting fermionic contributions. We add a quadratic term $\gamma \mathrm{tr}(A_{\mu }{A}^{\mu })$ in the action and calculate the expectation values of rotationally symmetric (or Lorentz symmetric) observables as a function of the coefficient $\gamma$. Our results exhibit striking differences between the two models around $\gamma =0$ and in the $\gamma >0$ region associated with the appearance of different saddle points, clearly demonstrating their inequivalence against naive expectations from quantum field theory.

This Letter presents the measurement of the energy-dependent neutrino-nucleon cross section in tungsten and the differential flux of muon neutrinos and antineutrinos. The analysis is performed using proton-proton collision data at a center-of-mass energy of 13.6 TeV and corresponding to an integrated luminosity of $(65.6\pm 1.4){\mathrm{fb}}^{-1}$. Using the active electronic components of the FASER detector, $338.1\pm 21.0$ charged current muon neutrino interaction events are identified, with backgrounds from other processes subtracted. We unfold the neutrino events into a fiducial volume corresponding to the sensitive regions of the FASER detector and interpret the results in two ways: (i) we use the expected neutrino flux to measure the cross section, and (ii) we use the predicted cross section to measure the neutrino flux. Both results are presented in six bins of neutrino energy, achieving the first differential measurement in the TeV range. The observed distributions align with standard model predictions. Using this differential data, we extract the contributions of neutrinos from pion and kaon decays.

Ever since the advent of quantum mechanics, tunneling has been an intriguing topic and consequently extensively studied and utilized. Investigating both theoretically and experimentally the nonadiabatic tunneling in strong-field ionization across a wide range of laser intensities, we unravel under-the-barrier-recollision dynamics leading to Freeman resonances (FR). The under-the-barrier-recollision model, which goes beyond the traditional direct multiphoton transition description, predicts distinct features of FR phenomena that cannot be explained by the existing direct multiphoton transition scenario. Specifically, it predicts (i) the dominance of high-order FR over above-threshold ionization in the photoelectron energy spectra and (ii) the flat dependence of the FR signal on the laser intensity, both in the nonadiabatic tunneling regime. This Letter experimentally demonstrates these features, corroborating the under-the-barrier-recollision model, and provides intuition into this dynamics, expanding our insights into the control of tunneling dynamics in laser spectroscopy and attosecond physics.

Polarons are crucial for charge transport in semiconductors, significantly impacting material properties and device performance. The dynamics of small polarons can be investigated using first-principles molecular dynamics. However, the limited timescale of these simulations presents a challenge for adequately sampling infrequent polaron hopping events. Here, we introduce a message-passing neural network combined with first-principles molecular dynamics within the Born-Oppenheimer approximation that learns the polaronic potential energy surface by encoding the polaronic state, allowing for simulations of polaron hopping dynamics at the nanosecond scale. By leveraging the statistical significance of the long timescale, our framework can accurately estimate polaron (anisotropic) mobilities and activation barriers in prototypical polaronic oxides across different scenarios (hole polarons in rocksalt MgO and electron polarons in pristine and F-doped rutile ${\mathrm{TiO}}_2$) within experimentally measured ranges.

We report an extensive high-field study of atacamite ${\mathrm{Cu}}_2\mathrm{Cl}{(\mathrm{OH})}_3$, a material realization of quantum sawtooth chains with weak interchain couplings, in continuous and pulsed magnetic fields up to 58 T. In particular, we have mapped the entropy landscape for fields as high as 35 T and have identified a field-induced quantum critical point at 21.9(1) T for $\mathbf{H}\parallel c$ axis. The quantum critical point separates field regions with and without magnetic order, evidenced by our thermodynamic study and ${}^1\mathrm{H}$ nuclear magnetic resonance spectroscopy, but lies far below full saturation of the magnetization. Corroborated by numerical results using density-matrix renormalization group calculations, we find this behavior associated with a dimensional reduction of the spin system: the sawtooth chain effectively decouples into an antiferromagnetic spin-$1/2$ chain (backbone of the sawtooth chain) in the presence of an exchange field produced by the remaining field-polarized spins.

Recently, it was shown that strongly driven micromechanical resonators show mode shapes that strongly differ from the eigenmodes [F. Yang et al., Spatial modulation of nonlinear flexural vibrations of membrane resonators, Phys. Rev. Lett. 122, 154301 (2019)]. This raises the question of the origin of this nonlinear behavior. We measure the spatial dependence of the nonlinearities of high-stress micromechanical membranes. The mechanical nonlinearity is determined from the frequency response and is found to be independent of the probing location. It is the phase of the response that is instrumental in extracting that intrinsic nonlinearity. Our interferometric readout results in high-harmonics generation. These harmonics have a clear spatial profile that shows ringlike patterns resembling previous reports. These patterns are reproduced by a model of the displacement-dependent reflection signal in combination with motion amplitudes of the same order as the probing wavelength.