Convection in planets and stars is predicted to occur in the “ultimate regime” of diffusivity-free, rapidly rotating turbulence in which flows are unaffected by viscous and thermal diffusion. Boundary layer diffusion, however, has historically hindered experimental access to this regime. Here, we utilize the boundary-independent oscillatory thermal-inertial mode of rotating convection to realize the diffusivity-free scaling in liquid metal laboratory experiments with additional validation from direct numerical simulations. This oscillatory style of convection arises in rotating liquid metals (low Prandtl number fluids) and is driven by the temperature gradient in the fluid bulk, thus remaining independent of diffusive boundary dynamics. We triply verify the existence of the diffusivity-free regime via measurements of heat transfer efficiency $Nu$, dimensionless flow velocities $Re$, and internal temperature anomalies $\theta$, all of which are in quantitative agreement with planar asymptotically reduced models. Realizing theoretical diffusivity-free scalings in desktop-sized laboratory experiments provides the validation necessary to extrapolate and predict the convective flows in remote geophysical and astrophysical systems.

Recent advances in time- and angle-resolved photoemission spectroscopy (tr-ARPES) allow for the probing of multiparticle excited states in reciprocal space. While neutral two-particle excitations (excitons) have been observed in tr-ARPES, signatures of trions—three-quasiparticle bound states—have only been probed via optical spectroscopy. Here, we develop a general theory for the ARPES signature of trions in the model system of a monolayer transition metal dichalcogenide (TMD). We simulate the ARPES signals of both positively and negatively charged trions and show that the interaction of the residual holes, or electron and hole, lead to large energy shifts, on the order of the exciton binding energy, compared to the exciton signal. For positive trions, the additional momentum degree of freedom of the residual particles leads to distinctive asymmetric line shapes. For negative trions, the photoemission process causes the tr-ARPES spectrum to reproduce inverted images of the exciton band structure for multiple exciton states, encompassing both spin-allowed and spin-forbidden states, providing a direct momentum-resolved probe of both trion and exciton physics.

The welding of two molten polyethylene films followed by their crystallization is studied using molecular dynamics simulations. The melts are composed of chains with either 200 or 2000 coarse-grained ethylene monomers, i.e., two carbons and their associated hydrogens lumped into a single bead. During melt welding, orientational and entanglement inhomogeneities caused by the preexisting film surfaces are resolved on molecular diffusion timescales. Crystallization of partially interdiffused films strongly amplifies the residual melt orientational anomalies, leading to higher crystallinity near the weld line. This phenomenon is unique to semicrystalline polymers and is expected to cause long-lived inhomogeneities in the structure of the welded interfacial region.

Low-dimensional ferroelectrics are attractive for their promising prospects in nanoelectronics. Compared with widely used ferroelectric perovskites, most low-dimensional ferroelectrics exhibit several inborn weaknesses such as small bandgaps (mostly $<2\mathrm{eV}$, i.e., semiconductorslike) or faint polarizations (e.g., $<1\mathrm{\mu }\mathrm{C}/{\mathrm{cm}}^2$ for sliding ferroelectrics even if their bandgaps can be large). Here we experimentally demonstrate the room-temperature ferroelectricity of van der Waals ${\mathrm{WO}}_2{\mathrm{Cl}}_2$. The well-tested $d^0$ rule inherited from ferroelectric perovskites leads to a large dipole ($\sim 3\mathrm{e}\AA$) from the off-center displacement of ${\mathrm{W}}^{6+}$ ion and a wide bandgap of 2.80 eV. Its ferroelectricity is proved by multiple characterizations including second harmonic generation, piezoresponse force microscopy, and ferroelectric hysteresis loops. More interestingly, the exotic noncollinear dipole order is directly observed at the atomic level by integrated differential phase contrast scanning transmission electron microscopy. Our Letter paves an alternative route for low-dimensional ferroelectrics to pursue excellent ferroelectric performance and distinct physics of polarity.

We demonstrate a method for generating entanglement between trapped atomic ions based on adiabatically ramped state-dependent forces. By ramping both the amplitude of the state-dependent force and the motional mode frequencies, we realize an entangling operation that is robust to motional mode occupation and drifts in the mode frequencies. We measure Bell state fidelities above 0.99 across a broad range of ramp parameters and with motional occupations up to ten phonons. This technique enables high-fidelity entangling operations without ground-state cooling, has a reduced calibration overhead, and is well suited for both quantum logic spectroscopy applications and scalable quantum computing architectures.

For achieving scalable and flexible quantum communication, a parallel quantum operation based on naturally spatially separable quantum resources is needed. In this Letter, we experimentally realize hundred-channel reconfigurable quantum teleportation with naturally spatially separable channels by integrating programmable holographic encoding with measurement-free all-optical feedforward. Specifically, programmable holographic engineering based on the weighted Gerchberg-Saxton algorithm is used to generate a reconfigurable $10\times 10$ optical array of 100 independently addressable spatial modes, forming naturally spatially separable quantum channels. A measurement-free all-optical feedforward then enables the parallel transfer of quantum information across all channels. Within this architecture, we successfully teleport the entire 100-mode optical array and an image with fidelities beating the corresponding classical limits. Our results offer a viable route for realizing parallel quantum information processing.

In this Letter, we directly measure the spatial variation of the saturation concentration along the interface of a binary droplet, showing that it is not uniform. This observation challenges the core assumption of classical evaporation theory, where a uniform interfacial saturation concentration leads to the edge-dominant evaporative flux responsible for the well-known coffee-ring effect in single-component droplets. Our interferometric measurements reveal that this assumption breaks down in multicomponent droplets, requiring a different framework to describe their evaporation behavior. By comparing the local evaporative flux with internal flow fields obtained using micro-particle image velocimetry, we show that changes in interfacial composition and flow pattern are closely coupled, leading the maximum evaporative flux to shift away from the contact line during evaporation. Recognizing that the maximum flux no longer resides at the edge is therefore essential for developing a correct and predictive understanding of evaporation in binary and more complex multicomponent droplets.

Despite enormous expenditures in the research field, the electron-doped side of nickelate superconductors remains uncharted territory. Substituting the trivalent rare-earth cations by a tetravalent one hitherto failed. Here, we demonstrate by first-principles calculations a disorder-free route to electron dope Ruddlesden-Popper nickelates. When intercalating wide-band-gap insulating layers such as $\mathrm{La}X{\mathrm{O}}_3$ ($X=\mathrm{Al}$, Ga, Sc) into ${\mathrm{La}}_2{\mathrm{NiO}}_4$, the extra ${(\text{LaO})}^{+}$ layers act as electron donors, releasing carriers into the Ni-$3d$ orbitals. This electron doping puts ${\mathrm{La}}_2{\mathrm{NiO}}_4:{\text{La}}_2{\mathrm{AlO}}_4$ naturally in the optimal region for $d_{x^2-y^2}$-wave superconductivity with $T_{\mathrm{c}}$ exceeding 50 K. The same concept also allows us to electron dope ${\mathrm{La}}_3{\text{Ni}}_2{\mathrm{O}}_7$, the superconductor in the limelight.

Spin-triplet topological superconductors are rare but of fundamental interest as they can host Majorana bound states that can be used in fault-tolerant quantum computing. Recent efforts have been devoted to searching for spin-triplet states in U-based compounds, but these materials have a low transition temperature ($T_{\mathrm{c}}$) and coexisting competing orders, which creates significant experimental challenges and often leads to contradictory conclusions. The Cr-based candidate ${\mathrm{K}}_2{\mathrm{Cr}}_3{\mathrm{As}}_3$ offers a promising alternative: it has a much higher $T_{\mathrm{c}}\ge 6.2\mathrm{K}$ and no magnetic order. Here we report a hallmark signature of spin-triplet superconductivity arising from the internal spin degrees of freedom via nuclear magnetic resonance measurements, and demonstrate the high tunability of the topological phases. We discovered three distinct superconducting phases and revealed the evolution of the paired-spins direction [$\mathbf{d}(\mathbf{k})$-vector]. At low magnetic fields, ${\mathrm{K}}_2{\mathrm{Cr}}_3{\mathrm{As}}_3$ evolves from a helical (Phase A) to a chiral state (Phase B) with a rotation of the $\mathbf{d}(\mathbf{k})$-vector from in-plane to out-of-plane direction upon cooling, although both phases have point nodes in the gap. A line-nodal gap is realized in the high-field Phase C, where the $\mathbf{d}(\mathbf{k})$-vector lies in the basal plane. These findings establish ${\mathrm{K}}_2{\mathrm{Cr}}_3{\mathrm{As}}_3$ as a model spin-triplet superconductor and a promising platform for manipulating topological phases.

Single-molecule force spectroscopy resolves folding dynamics one molecule at a time, but extracting quantitative free-energy landscapes typically requires extensive datasets and careful instrument calibration to disentangle the molecule from linker and apparatus artifacts. We introduce a simulation-based inference framework that combines physics-based modeling with deep learning to recover the Bayesian posterior of a folding model directly from a single short trajectory. A 2-s constant-force measurement of a DNA hairpin is sufficient to reconstruct the folding landscape, matching deconvolution baselines that require 20–100 times more data and eliminating separate linker or instrument characterization. The same approach recovers four metastable states of a riboswitch aptamer from a single 5-s trajectory. Every parameter, including diffusion coefficients and linker stiffness, is included in the calibrated posterior. The current implementation assumes one-dimensional Markovian dynamics, but more complex models can be substituted within the same framework, opening single-molecule force spectroscopy to high-throughput parallel experiments and to systems where extensive data collection is impractical.

The bilayer nickelate ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ has recently emerged as a high-temperature superconductor with unusual spin stripe order in its ambient pressure phase. We propose a microscopic Hamiltonian that faithfully reflects the crystalline symmetry of this system, with the primary aim of addressing its unconventional magnetism at ambient pressure. Using state-of-the-art density matrix renormalization group calculations, we show that $(\pi /2,\pi /2)$ spin stripe order arises in our model at sizable Hund’s coupling $J_H$ from a hidden quasi one-dimensionality and persists over a range of electron concentrations. In the more symmetric high-pressure regime, our model exhibits enhanced interlayer pairing tendencies when the interlayer antiferromagnetic coupling $J_{\perp }$ becomes sufficiently large. Our results provide a microscopic origin of the diagonal spin stripes and identify Hund’s coupling $J_H$ and interlayer coupling $J_{\perp }$ as key ingredients governing magnetic order and pairing tendencies in ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$.

Over the past several decades, dozens of tests have sought the 132 Lorentz-violating degrees of freedom in the nonrelativistic limit of the minimal matter sector of the standard-model extension, yet 43 remained unconstrained. In this Letter, we limit all previously unconstrained degrees of freedom and make improvements on 13 prior limits. The approach introduced here offers the potential of further improvements for 49 degrees of freedom in suitable future experiments, along with additional discovery potential offered by combining data from experiments performed in different locations.

A central question in strong-interaction physics, governed by quantum chromodynamics (QCD), is whether femtoscale droplets of quark-gluon plasma form in small collision systems involving projectiles significantly smaller than heavy ions. Collisions of light ions such as ${}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}$ offer a unique opportunity to probe the emergence of collective behavior in QCD matter. This Letter presents the first measurements of the elliptic ($v_2$) and triangular ($v_3$) flow of charged particles in ${}^{16}\mathrm{O}–{}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}–{}^{20}\mathrm{Ne}$ collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=5.36\mathrm{TeV}$ with the ALICE detector. The hydrodynamic model predictions, explicitly incorporating the nuclear structures of ${}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}$, exhibit a good agreement with the flow measurements presented. The observed increase of $v_2$ in central Ne–Ne collisions relative to OO collisions, driven by the nuclear geometries, highlights the importance of utilizing light nuclei with well-defined geometric shapes to constrain the initial conditions. These findings support the presence of nuclear geometry-driven hydrodynamic flow in light-ion collisions at the LHC.

The long-range collective flow of particles produced in oxygen-oxygen ($\mathrm{O}+\mathrm{O}$) and neon-neon ($\mathrm{Ne}+\mathrm{Ne}$) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of $7{\mathrm{nb}}^{-1}$ and $0.8{\mathrm{nb}}^{-1}$ for $\mathrm{O}+\mathrm{O}$ and $\mathrm{Ne}+\mathrm{Ne}$ collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic ($v_2$) and triangular ($v_3$) flow harmonics are observed in both systems. The ratios of $v_n$ coefficients between $\mathrm{Ne}+\mathrm{Ne}$ and $\mathrm{O}+\mathrm{O}$ collisions suggest sensitivity to the intrinsic nuclear structure of the respective Ne and O ions. Hydrodynamic models with ab initio nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the $v_n$ values and the $\mathrm{Ne}+\mathrm{Ne}$ to $\mathrm{O}+\mathrm{O}$ ratios. These measurements provide new constraints when modeling the interplay of nuclear structure and collective dynamics in collisions of ${}^{16}\mathrm{O}$ and ${}^{20}\mathrm{Ne}$ ions, respectively.

The ground-state rotational band of ${}^{252}\mathrm{Fm}$ ($Z=100$, $N=152$) was investigated using two different experimental setups at the JAEA Tandem Accelerator Laboratory. The $2^{+}\to 0^{+}$ and $4^{+}\to 2^{+}$ transitions were observed in the $\alpha$ decay of ${}^{256}\mathrm{No}$ via $\alpha \text{−}\gamma$ coincidence spectroscopy. The energies of the $(6^{+})\to (4^{+})$, $(8^{+})\to (6^{+})$, and $(10^{+})\to (8^{+})$ transitions were identified in the prompt $\gamma$-ray spectrum of ${}^{252}\mathrm{Fm}$ produced in the ${}^{18}\mathrm{O}+{}^{249}\mathrm{Cf}$ multinucleon transfer reaction. The new data reveal that, compared with neighboring fermium isotopes and $N=152$ isotones in the region, ${}^{252}\mathrm{Fm}$ has the lowest first excited $2^{+}$-state energy, 41.88(16) keV, and the largest kinematic moment of inertia. These properties constitute new evidence for the deformed shell gaps at $Z=100$ and $N=152$, supporting the understanding of ${}^{252}\mathrm{Fm}$ as a deformed doubly magic nucleus.

The layered compound $\gamma \text{−}{\mathrm{PtBi}}_2$ is a topological semimetal with Fermi arcs at the surface joining bulk Weyl points. Recent work has found signatures of surface superconductivity consisting of gap openings compatible with a critical temperature orders of magnitude larger than the bulk value. However, no superconducting vortices have been identified, raising questions about the robustness of the phase coherence. Here, we use very low temperature STM and find robust superconductivity with ${\mathrm{T}}_C=2.9\mathrm{K}$ and ${\mathrm{H}}_{C2}\approx 1.8\mathrm{T}$ linked to the Fermi arcs. We observe quantized superconducting vortices and the Josephson effect, demonstrating two-dimensional macroscopic quantum phase coherence.

The vertical redistribution of materials in the lunar regolith—ranging from continuously produced space-weathering products to sporadic pulses of supernova- or kilonova-derived isotopes—remains a fundamental problem in planetary science. We present a unified stochastic model of regolith gardening induced by the impact flux. Treating gardening as a competition between impact-driven advection and diffusion predicts the maturity profiles of Apollo cores over more than 2 orders of magnitude in time ($1.4\times {10}^7$ to $4.5\times {10}^8\mathrm{yr}$). This model describes well the depth profiles of live ${}^{60}\mathrm{Fe}$ in Apollo regolith samples, suggesting that supernova dust capture is independent of native iron abundance, and is consistent with a uniform influx at the latitudes of the Apollo landing sites. We extend our model to predict lunar signals for live $r$-process species that might originate from supernovae or kilonovae: ${}^{244}\mathrm{Pu}$ tied to terrestrial detections, and ${}^{129}\mathrm{I}$, ${}^{182}\mathrm{Hf}$, and ${}^{247}\mathrm{Cm}$ based on $r$-process calculations. The ${}^{244}\mathrm{Pu}/{}^{60}\mathrm{Fe}$ depth profile can probe the origin of ${}^{244}\mathrm{Pu}$, motivating searches in Artemis regolith samples down to depths $\mathcal{O}(100)\mathrm{cm}$.

We prove the existence of spontaneous symmetry breaking in suitably low-energy eigenstates of certain gapless and frustrated many-body quantum systems, namely symmetric quantum perturbations to classical models that exhibit spontaneous symmetry breaking of a finite group at some positive temperature. Additionally, the classical model need not be local in space, as long as it satisfies a quantum analog of the Peierls condition. As an example of our technique, we establish robust ferromagnetism in random-bond Ising models in $d=2$ dimensions with sufficiently biased random couplings, with weak transverse field. Our mathematical technique is based on establishing quantum bottlenecks, similar to a “many-body Wentzel-Kramers-Brillouin” method for evaluating tunneling rates. Using these same methods, we provide new proofs of metastability and the slow decay of the false vacuum, applicable to gapless metastable states. Our Letter represents a first step toward a rigorous classification of stable gapless quantum phases.

We present a high-precision calculation of the hadronic running of electroweak gauge couplings from first principles. Employing lattice QCD in the low-energy regime, we achieve permille precision for virtualities $Q^2\lesssim 12{\mathrm{GeV}}^2$. At $Q^2\simeq 1{\mathrm{GeV}}^2$, our determination deviates by up to $7\sigma$ from estimates based on $e^{+}{e}^{-}$ measurements. Combining lattice QCD with perturbative QCD via the Euclidean split technique, we obtain for the electromagnetic coupling $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)=0.027821(34{)}_{\mathrm{lat}}(35{)}_{\text{pQCD}}$, which is more than twice as precise as recent phenomenological determinations. We assess improvement scenarios by which the precision target for next-generation electroweak measurements could be reached.

Energetic quarks and gluons traversing a hot and dense quark-gluon plasma deposit energy and momentum into the medium before hadronizing to collimated sprays of particles, known as jets. This energy-momentum deposition is expected to produce medium responses, collectively known as jet wakes, with “diffusion wake” denoting a depletion of particles in the direction opposite to the propagating jet. The diffusion wake is studied by comparing dijet-hadron correlations measured in lead-lead (PbPb) and proton-proton (pp) collisions. The analysis uses PbPb and pp data recorded at a nucleon-nucleon (NN) center-of-mass energy $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$ with the CMS detector at the CERN LHC. By exploring how the dijet-hadron correlation distributions differ for various pseudorapidity separations of the two jets in the dijet, the presence of a jet diffusion wake is firmly established. The diffusion wake signal has a significance greater than 5 standard deviations for charged particles in the transverse momentum range $1<p_{\mathrm{T}}<2\mathrm{GeV}$. The measurements are compared with model predictions with and without jet wake effects, providing new insights into quark-gluon plasma properties and the formation of jet-induced wakes.