We report a mechanism of lateral manipulation of single Fe adatoms on the surface of the topological insulator ${\mathrm{Bi}}_2{\mathrm{Se}}_3$ with atomic force microscopy. The Fe atoms are embedded within the sparsely packed surface layer, rendering them inaccessible to classical manipulation methods. Nevertheless, we find a manipulation mechanism in which the Fe atom is plucked from its adsorption site and can be pulled along the surface. We demonstrate the controllability of this pluck-pull manipulation by the construction of a small nanostructure.

Emergent collective modes in lattices give birth to many intriguing physical phenomena in condensed matter physics. Among these collective modes, large-area modes typically feature small-level spacings, while a mode with stable frequency tends to be spatially tightly confined. In this Letter, we theoretically propose and experimentally demonstrate a symmetry-related large-area topological corner mode with a tunable mode area and stable frequency. This mode emerges from the hybridization of the homogeneous Dirac point mode and in-gap topological corner modes. Remarkably, this hybridized mode possesses unique chirality related to the chiral symmetry. We experimentally observe such hybridized mode in a two-dimensional (2D) photonic system and demonstrate its robustness by introducing disorders in the structure. Our findings advance the frontier of higher-order topology research, transitioning it from single-lattice systems to hybridized multilattice systems. These results may support promising potential applications, particularly in vertical-cavity surface-emitting lasers.

We show that the generalized geometry formalism provides a new approach to the description of higher-fermion terms in $𝒩=1$ supergravity in ten dimensions, which does not appeal to supercovariantization or superspace. We find expressions containing only five higher-fermion terms across the action and supersymmetry transformations, working in the second-order formalism.

Nuclear medium effects on $B^{+}$ meson production are studied using the binary-collision scaled cross section ratio between events of different charged-particle multiplicities from proton-lead collisions. Data, collected by the CMS experiment in 2016 at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}=8.16\mathrm{TeV}$, corresponding to an integrated luminosity of $175{\mathrm{nb}}^{-1}$, were used. The scaling factors in the ratio are determined using a novel approach based on the $Z\to {\mu }^{-}{\mu }^{+}$ cross sections measured in the same events. The scaled ratio for $B^{+}$ is consistent with unity for all event multiplicities, putting stringent constraints on nuclear modification for heavy flavor.

We study the properties of gluon plasma subjected to a weak acceleration using first-principles numerical Monte Carlo simulations. We use the Luttinger (Tolman-Ehrenfest) correspondence between temperature gradient and gravitational field to impose acceleration in imaginary time formalism. Under acceleration, the system resides in global thermal equilibrium. Our results indicate that even the weakest acceleration up to $a\simeq 16\mathrm{MeV}$ drastically softens the deconfinement phase transition, converting the first-order phase transition of a static system to a soft crossover for accelerating gluons. The accelerating environment can be relevant to the first moments of the early Universe and the initial glasma regime of relativistic heavy ion collisions. In particular, our results imply that the acceleration, if present, may also inhibit the detection of the thermodynamic phase transition from quark-gluon plasma to the hadronic phase.

Low-dimensional spin fluctuations play a crucial role in unconventional superconductors, with quasi-one-dimensional spin excitations potentially linked with spin-triplet superconductivity. The heavy fermion superconductor ${\mathrm{CeSb}}_2$ exhibits an unusual large inverted $S$-shaped upper critical field that suggests a possible triplet pairing state within its pressure-induced superconducting dome. Using inelastic neutron scattering, we discover quasi-one-dimensional magnetic excitations in ${\mathrm{CeSb}}_2$ emerging from nearly square Ce layers with minor orthorhombic deformation. We show that the data are well described by a ferromagnetic spin ladder model, where the “rungs” of the ladder straddle Ce bilayers. Moreover, we find that diffuse excitations akin to those in the ordered phase persist well above $T_{\mathrm{N}}$, suggesting that quasi-one-dimensional ferromagnetic paramagnons may significantly contribute to the unusual superconductivity that appears under pressure once magnetic order is suppressed.

A quantum limit on the measurement of magnetic fields has been recently pointed out, stating that the so-called energy resolution $E_{\mathrm{R}}$ is bounded to $E_{\mathrm{R}}\gtrsim \hslash$. This limit indeed holds true for the vast majority of existing quantum magnetometers, including superconducting quantum interference devices and solid state spin and optically pumped atomic magnetometers. However, it can be surpassed by highly correlated spin systems, as recently demonstrated with a single-domain spinor BEC. Here, we show that similar and potentially much better resolution can be achieved with a hard ferromagnet levitated above a superconductor at cryogenic temperature. We demonstrate $E_{\mathrm{R}}=(0.064\pm 0.010)$ $\hslash$ and anticipate that $E_{\mathrm{R}}<{10}^{-3}$ $\hslash$ is within reach with near-future improvements. This finding opens the way to new applications in condensed matter, biophysics, and fundamental science. In particular, we propose an experiment to search for axionlike dark matter and project a sensitivity that is orders of magnitude better than in previous searches.

Light bosons, beyond the standard model and as prominent candidates for dark matter, can mediate velocity and spin dependent exotic interaction between electron spins and nucleons. At short ranges, it remains an open challenge to test this exotic interaction with high precision. Here, we present a method based on a diamagnetic-levitated force sensor to detect the exotic interaction at the millimeter scale. Improved constraints for the coupling $g_A^e{g}_V^N$ are established, within the force range spanning from 0.15 to 1.5 mm. The constraint $|g_A^e{g}_V^N|\le 4.39\times {10}^{-26}$ at $\lambda =0.5\mathrm{mm}$ at the 95% confidence level significantly surpasses previous results by more than 3 orders of magnitude. The diamagnetic levitation force measurement system developed here can also be repurposed to probe other exotic spin dependent interactions, such as the exotic spin-spin interaction. This system provides a platform for the exploration of dark matter.

Using $20.3{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy 3.773 GeV with the BESIII detector, we report the first observation of the semileptonic decay $D^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ with significance of $8.6\sigma$ including systematic uncertainties, and an improved measurement of $D^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$. The branching fractions of $D^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ and $D^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$ are determined to be $(1.92\pm 0.28_{\mathrm{stat}}\pm 0.08_{\mathrm{syst}})\times {10}^{-4}$ and $(1.79\pm 0.19_{\mathrm{stat}}\pm 0.07_{\mathrm{syst}})\times {10}^{-4}$, respectively. The ratio of the two branching fractions is determined to be ${\mathcal{R}}_{\mu /e}=1.07\pm 0.19_{\mathrm{stat}}\pm 0.03_{\mathrm{syst}}$, which agrees with the theoretical expectation of lepton flavor universality within the standard model. From an analysis of the $D^{+}\to {\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ decay dynamics, the product of the hadronic form factor $f_{+}^{{\eta }^{\prime }}(0)$ and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cd}|$ is measured for the first time, giving $f_{+}^{{\eta }^{\prime }}(0)|V_{cd}|=(5.92\pm 0.56_{\mathrm{stat}}\pm 0.13_{\mathrm{syst}})\times {10}^{-2}$. The $\eta -{\eta }^{\prime }$ mixing angle in the quark flavor basis is determined to be ${\varphi }_{\mathrm{P}}=(39.8\pm {0.8}_{\mathrm{stat}}\pm {0.3}_{\mathrm{syst}})°$.

We present the first ab initio calculation at physical quark masses of scattering amplitudes describing the lightest pseudoscalar mesons interacting via the strong force in the vector channel. Using lattice quantum chromodynamics, we postdict the defining parameters for two short-lived resonances, the $\rho (770)$ and $K^{*}(892)$, which manifest as complex energy poles in $\pi \pi$ and $K\pi$ scattering amplitudes, respectively. The calculation proceeds by first computing the finite-volume energy spectrum of the two-hadron systems and then determining the amplitudes from the energies using the Lüscher formalism. The error budget includes a data-driven systematic error, obtained by scanning possible fit ranges and fit models to extract the spectrum from Euclidean correlators, as well as the scattering amplitudes from the latter. The final results, obtained by analytically continuing multiple parametrizations into the complex energy plane, are $M_{\rho }=796(5)(50)\mathrm{MeV}$, ${\mathrm{\Gamma }}_{\rho }=192(10)(31)\mathrm{MeV}$, $M_{K^{*}}=893(2)(54)\mathrm{MeV}$, and ${\mathrm{\Gamma }}_{K^{*}}=51(2)(11)\mathrm{MeV}$, where the subscript indicates the resonance and $M$ and $\mathrm{\Gamma }$ stand for the mass and width, respectively, and where the first bracket indicates the statistical and the second bracket the systematic uncertainty.

Extending quantum control to increasingly complex systems is crucial for both advancing quantum technologies and fundamental physics. In trapped ion systems, quantum logic techniques that combine a well-controlled logic species with a more complex spectroscopy species have proven to be a powerful tool for extending the range of accessible species. Here, we demonstrate that a quantum system as complex as ${}^{48}{\mathrm{Ti}}^{+}$ with its many metastable states can be controlled employing a combination of intrinsic thermalization due to collisions with background gas and quantum-logic techniques using a far-detuned Raman laser. The preparation of pure quantum states allows coherent manipulation and high resolution measurements of the Zeeman structure in ${}^{48}{\mathrm{Ti}}^{+}$. The presented techniques are applicable to a wide range of ionic species giving access to a larger variety of systems for fundamental physics and constitute the first step for quantum-controlled spectroscopy of transition metals, relevant, e.g., for the interpretation of astrophysical spectra.

We experimentally and theoretically demonstrate that spinor gases driven by spin-flopping fields are excellent platforms for investigating ergodicity breaking and quantum scarring. We observe that specific initial states remain nonthermal at weak driving despite the majority of states thermalizing, which constitutes clear evidence of quantum many-body scars (QMBSs). As the driving strength increases, the experimental system undergoes a smooth transition from integrable to weakly ergodicity breaking, which supports QMBSs, and then to fully thermal. This is in agreement with the theoretical spectra, which predict towers of states dissolving with increasing driving strength. This Letter advances the study of QMBSs and quantum scars with applications to, e.g., quantum information storage.

Quantum geometric tensor (QGT), which is usually obtained by evaluating the quantum distance between Bloch states parametrized by momentum, plays a key role in exploring the exotic responses of quantum materials. Herein, we revisit the concept of QGT by further taking into account the spin degree of freedom. Besides the conventional QGT relating to momentum translation, we uncover a new QGT (termed Zeeman QGT) relating to momentum translation as well as spin rotation, whose imaginary (real) part gives the Zeeman Berry curvature (quantum metric). Notably, we show that these novel quantum geometric quantities can drive an intrinsic gyrotropic magnetic current (IGMC) in spin-orbit coupled materials when the electron spin is steered by an oscillating magnetic field. With symmetry analysis, we show that a wide range of materials can support the IGMC, as illustrated by model calculations. Finally, we discuss the experimental aspects of detecting the IGMC driven by Zeeman QGT.

The low-energy collective excitations of semiconductors and insulators often couple strongly to light, allowing them to be probed optically. We argue here that in fractional Chern insulators intraband collective excitations are dark in the sense that they couple anomalously weakly to light. Using this property, we establish a general relationship between flat-band Chern numbers, quantum geometry, and spatial correlations in fractional-Chern-insulator states.

The two-dimensional Hubbard model is widely believed to capture key ingredients of high-$T_c$ superconductivity in cuprate materials. However, compelling evidence remains elusive. In particular, various magnetic orders may emerge as strong competitors of superconducting orders. Here, we study the ground state properties of the doped two-dimensional $t\text{−}{t}^{\prime }$ Hubbard model on a square lattice via the infinite projected entangled-pair state method with U(1) or SU(2) spin symmetry. The former is compatible with antiferromagnetic orders, while the latter forbids them. Therefore, we obtain by comparison a detailed understanding of the magnetic impact on superconductivity. Moreover, an additional $t^{\prime }$ term accommodates the particle-hole asymmetry, which facilitates studies on the discrepancies between electron- and hole-doped systems. We demonstrate that (i) a positive $t^{\prime }/t$ significantly amplifies the strength of superconducting orders; (ii) at sufficiently large doping levels, the $t\text{−}{t}^{\prime }$ Hubbard model favors a uniform state with superconducting orders instead of stripe states with charge and spin modulations; and (iii) the enhancement of magnetic frustration, by increasing either the strength of next-nearest neighbor interactions or the charge doping, impairs stripe orders and helps stabilize superconductivity.