In hybrid systems where nanowires are proximity-coupled with superconductors, the low-energy theory fails to determine the topological phase with Majorana fermion (MF) when the magnetic field or proximity coupling is much stronger. To overcome this limitation, we propose a holistic approach that defines MF by considering both the motion of electrons in the nanowire and the quasiparticle excitations in the superconductor. This approach transcends the constraints of low-energy theory and offers broad applicability. Our approach reveals that the topological phase diagram depends not only on the chemical potential and Zeeman energy in the nanowire, but also on those in the superconductor, and the matched chemical potentials are more favorable for observing MF. This broader perspective provides specific experimental guidance under various conditions.

We show that the ground-state expectation value of twisting operator is a topological order parameter for U(1)- and ${\mathbb{Z}}_N$-symmetric symmetry-protected topological (SPT) phases in one-dimensional “spin” systems—it is quantized in the thermodynamic limit and can be used to identify different SPT phases and to diagnose phase transitions among them. We prove that this (nonlocal) order parameter must take values in $N$th roots of unity, and its value can be changed by a generalized lattice translation acting as an $N$-ality transformation connecting distinct phases. This result also implies the Lieb-Schultz-Mattis (LSM) ingappability for $\mathrm{SU}(N)$ spins if we further impose a general translation symmetry. Furthermore, our exact result for the order parameter of SPT phases can predict a large number of LSM ingappabilities by the general lattice translation. We also apply the $N$-ality property to provide an efficient way to construct possible multicritical phase transitions starting from a single Hamiltonian with a unique gapped ground state.

We introduce an approach for analyzing the responses of dynamical systems to external perturbations that combines score-based generative modeling with the generalized fluctuation-dissipation theorem. The methodology enables accurate estimation of system responses, including those with non-Gaussian statistics. We numerically validate our approach using time-series data from three different stochastic partial differential equations of increasing complexity: an Ornstein-Uhlenbeck process with spatially correlated noise, a modified stochastic Allen-Cahn equation, and the 2D Navier-Stokes equations. We demonstrate the improved accuracy of the methodology over conventional methods and discuss its potential as a versatile tool for predicting the statistical behavior of complex dynamical systems.

We introduce a change of perspective on tensor network states that is defined by the computational graph of the contraction of an amplitude. The resulting class of states, which we refer to as tensor network functions, inherit the conceptual advantages of tensor network states while removing computational restrictions arising from the need to converge approximate contractions. We use tensor network functions to compute strict variational estimates of the energy on loopy graphs, analyze their expressive power for ground states, show that we can capture aspects of volume law time evolution, and provide a mapping of general feed-forward neural nets onto efficient tensor network functions. Our work expands the realm of computable tensor networks to ones where accurate contraction methods are not available, and opens up new avenues to use tensor networks.

We employ the isomonodromic method to study linear scalar massive perturbations of Kerr black holes for generic scalar masses $M\mu$ and generic black hole spins $a/M$. We find that the longest-living quasinormal mode and the first overtone coincide for $(M\mu {)}_c\simeq 0.3704981$ and $(a/M{)}_c\simeq 0.9994660$. We also show that the longest-living mode and the first overtone change continuously into each other as we vary the parameters around the point of degeneracy, providing evidence for the existence of a geometric phase around an exceptional point. We interpret our findings through a thermodynamic analogy.

$Z$ boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from standard model predictions. All previous measurements of $Z$ boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins. In this analysis, a machine learning method called omnifold is used to produce a simultaneous measurement of twenty-four $Z+\text{jets}$ observables using $139{\mathrm{fb}}^{-1}$ of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ collected with the ATLAS detector. Unlike any previous fiducial differential cross-section measurement, this result is presented unbinned as a dataset of particle-level events, allowing for flexible reuse in a variety of contexts and for new observables to be constructed from the twenty-four measured observables.

A comprehensive study of the angular distributions in the bottom-baryon decays ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}(h=\pi ,K)$, followed by ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{h}^{+}$ with $\mathrm{\Lambda }\to p{\pi }^{-}$ or ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0$ decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The decay parameters and the associated charge-parity ($CP$) asymmetries are measured, with no significant $CP$ violation observed. For the first time, the ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}$ decay parameters are measured. The most precise measurements of the decay parameters $\alpha$, $\beta$, and $\gamma$ are obtained for ${\mathrm{\Lambda }}_c^{+}$ decays and an independent measurement of the decay parameters for the strange-baryon $\mathrm{\Lambda }$ decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays.

We have produced state selective molecular angular momentum orientation using dressed states created by a cw optical field. The experiment was carried out with ${\mathrm{Li}}_2$ molecules and a combination of left- and right-hand circularly polarized lasers. Our approach exploits the dependence of the Rabi frequency on the quantum number $M$, which makes it possible to achieve complete $M$-state selectivity and thus molecular angular momentum orientation relative to laboratory frame space-fixed axes. Using molecules in a ${}^1\mathrm{\Sigma }$ state, orientation of the rotational angular momentum, $\overrightarrow{R}$, can be achieved by spectrally resolving the Autler-Townes split $M$ components of the total angular momentum, $\overrightarrow{J}$.

The bismuth monolayer has recently been experimentally identified as a novel platform for the investigation of two-dimensional single-element ferroelectric system. Here, we model the potential energy surface of a bismuth monolayer by employing a message-passing neural network and achieve an error smaller than 1.2 meV per atom. Empowered by the high accuracy and fast prediction of the machine learning model, we have embarked on in-depth and large-scale atomistic simulations. These explorations are tailored to understand the temperature-dependent phase transitions, with an emphasis on the difference between free-standing monolayers and those constrained by a substrate. Furthermore, with the large system used in the simulations, we are also able to observe ferroelectric domains within these systems and shed light on their intrinsic lattice thermal conductivity.

We observe divergent temperature-dependent magnetic resonance relaxation behaviors across various brine-saturated porous materials. The paramagnetic and diamagnetic nature of the samples underlies these divergent behaviors. The temperature-dependent trends of the longitudinal $T_1$ and transverse $T_2$ relaxation times are systematically explained via distinct relaxation-diffusion regimes of Brownstein-Tarr theory. Water diffusivity is a key determinant of the behavior. While systematic temperature-dependent relaxation trends were observed with the majority of the samples, a minority showed temperature independence. This was attributed to the transition of relaxation behaviors between distinct relaxation-diffusion regimes. The temperature dependence observed reinforces the notion that Brownstein-Tarr theory describes the full gamut of relaxation behaviors in fluid saturated porous media.

The two-dimensional electron gas (2DEG) is a fundamental model, which is drawing increasing interest because of recent advances in experimental and theoretical studies of 2D materials. Current understanding of the ground state of the 2DEG relies on quantum Monte Carlo calculations, based on variational comparisons of different Ansätze for different phases. We use a single variational ansatz, a general backflow-type wave function using a message-passing neural quantum state architecture, for a unified description across the entire density range. The variational optimization consistently leads to lower ground-state energies than previous best results. Transition into a Wigner crystal (WC) phase occurs automatically at $r_s=37\pm 1$, a density lower than currently believed. Between the liquid and WC phases, the same ansatz and variational search strongly suggest the existence of intermediate states in a broad range of densities, with enhanced short-range nematic spin correlations.

Non-Hermiticity gives rise to distinctive topological phenomena absent in Hermitian systems. However, connection between such intrinsic non-Hermitian topology and Hermitian topology has remained largely elusive. Here, considering the bulk and boundary as an environment and system, respectively, we demonstrate that anomalous boundary states in Hermitian topological insulators exhibit non-Hermitian topology. We study the self-energy capturing the particle exchange between the bulk and boundary, and show that it detects Hermitian topology in the bulk and induces non-Hermitian topology at the boundary. As an illustrative example, we reveal non-Hermitian topology and concomitant skin effect inherently embedded within chiral edge states of Chern insulators. We also identify the emergence of hinge states within effective non-Hermitian Hamiltonians at surfaces of three-dimensional topological insulators. Furthermore, we comprehensively classify our correspondence across all the tenfold symmetry classes of topological insulators and superconductors. Our Letter uncovers hidden connection between Hermitian and non-Hermitian topology, and provides an approach to identifying non-Hermitian topology in quantum matter.

The emergence of a quantum spin liquid (QSL), a state of matter that can result when electron spins are highly correlated but do not become ordered, has been the subject of a considerable body of research in condensed matter physics [1,2]. Spin liquid states have been proposed as hosts for high-temperature superconductivity [3] and can host topological properties with potential applications in quantum information science [4]. The excitations of most quantum spin liquids are not conventional spin waves but rather quasiparticles known as spinons, whose existence is well established experimentally only in one-dimensional systems; the unambiguous experimental realization of QSL behavior in higher dimensions remains challenging. Here, we investigate the novel compound ${\mathrm{YbZn}}_2{\mathrm{GaO}}_5$, which hosts an ideal triangular lattice of effective spin-$1/2$ moments with no detectable inherent chemical disorder. Thermodynamic and inelastic neutron scattering measurements performed on high-quality single crystal samples of ${\mathrm{YbZn}}_2{\mathrm{GaO}}_5$ exclude the possibility of long-range magnetic ordering down to 0.06 K, demonstrate a quadratic power law for the specific heat and reveal a continuum of magnetic excitations in parts of the Brillouin zone. Both low-temperature thermodynamics and inelastic neutron scattering spectra suggest that ${\mathrm{YbZn}}_2{\mathrm{GaO}}_5$ is a $U(1)$ Dirac QSL with spinon excitations concentrated at certain points in the Brillouin zone. We advanced these results by performing additional specific heat measurements under finite fields, further confirming the theoretical expectations for a Dirac QSL on the triangular lattice of ${\mathrm{YbZn}}_2{\mathrm{GaO}}_5$.

The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog of the LL dynamics has been proposed in [Phys. Rev. Lett. 110, 147201 (2013)], the corresponding quantum version of LLG remains unknown. Here, we propose such a quantum LLG equation that inherently conserves purity of the quantum state. We examine the quantum LLG dynamics of a dimer consisting of two interacting spin-$\frac{1}{2}$ particles. Our analysis reveals that, in the case of ferromagnetic coupling, the evolution of initially uncorrelated spins mirrors the classical LLG dynamics. However, in the antiferromagnetic scenario, we observe pronounced deviations from classical behavior, underscoring the unique dynamics of becoming a spinless state, which is nonlocally correlated. Moreover, when considering spins that are initially entangled, our study uncovers an unusual form of revival-type quantum correlation dynamics, which differs significantly from what is typically seen in open quantum systems.

Precisely engineered gigahertz surface acoustic wave (SAW) trapping enables diverse and controllable interconnections with various quantum systems, which are crucial to unlocking the full potential of phonons. The topological rainbow based on synthetic dimension presents a promising avenue for facile and precise localization of SAWs. In this study, we successfully developed a monolithic gigahertz SAW topological rainbow by utilizing a nanoscale translational deformation as a synthetic dimension. We observed a gapless topological boundary state, which originates from a $2\pi$ phase winding in the Zak phase during translation. These boundary states enable on-chip single-mode rainbowlike filters with an extensive range of adjustable operating frequencies. Furthermore, we construct nanoscale wedge-shaped grooves, realizing the Born-von-Karman interface. The interface generates topological rainbow resonators with high quality and small mode volume, which can trap topological phononic states of different frequencies into different positions. This study underscores the immense potential of topological acoustics in synthetic dimensions for microwave acoustics, providing a robust design framework for the precise manipulation of SAWs.

Exploring continuous time crystals (CTCs) within the symmetric subspace of spin systems has been a subject of intensive research in recent times. Thus far, the stability of the time-crystal phase outside the symmetric subspace in such spin systems has gone largely unexplored. Here, we investigate the effect of including the asymmetric subspaces on the dynamics of CTCs in a driven dissipative spin model. This results in multistability, and the dynamics becomes dependent on the initial state. Remarkably, this multistability leads to exotic synchronization regimes such as chimera states and cluster synchronization in an ensemble of coupled identical CTCs. Interestingly, it leads to other nonlinear phenomena such as oscillation death and signature of chaos.

Josephson junction parametric amplifiers have become essential tools for microwave quantum circuit readout with minimal added noise. Even after improving at an impressive rate in the past decade, they remain vulnerable to magnetic fields, which limits their use in many applications such as spin qubits, Andreev and molecular magnet devices, dark matter searches, etc. Kinetic inductance materials, such as granular aluminum (grAl), offer an alternative source of nonlinearity with innate magnetic field resilience. We present a nondegenerate amplifier made of two coupled grAl resonators resilient to in-plane magnetic fields up to 1T. It offers 20 dB of gain close to the quantum limit of added noise, with a gain-bandwidth product of 28 MHz and $-110\mathrm{dBm}$ input saturation power.

We present a method to systematically identify and classify quantum optical nonclassical states as classical or nonclassical based on the resources they create on a bosonic quantum computer. This is achieved by converting arbitrary bosonic states into multiple modes, each occupied by a single photon, thereby defining qubits of a bosonic quantum computer. Starting from a bosonic classical-like state in a representation that explicitly respects particle number superselection rules, we apply universal gates to create arbitrary superpositions of states with the same total particle number. The nonclassicality of the corresponding states can then be associated with the operations they induce in the quantum computer. We also provide a correspondence between the adopted representation and the more conventional one in quantum optics, where superpositions of Fock states describe quantum optical states, and we identify how multimode states can lead to quantum advantage. Our work contributes to establish a seamless transition from continuous to discrete properties of quantum optics while laying the grounds for a description of nonclassicality and quantum computational advantage that is applicable to spin systems as well.

The spin-exotic hybrid meson ${\pi }_1(1600)$ is predicted to have a large decay rate to the $\omega \pi \pi$ final state. Using $76.6{\mathrm{pb}}^{-1}$ of data collected with the GlueX detector, we measure the cross sections for the reactions $\gamma p\to \omega {\pi }^{+}{\pi }^{-}p$, $\gamma p\to \omega {\pi }^0{\pi }^{0}p$, and $\gamma p\to \omega {\pi }^{-}{\pi }^0{\mathrm{\Delta }}^{++}$ in the range $E_{\gamma }=8–10\mathrm{GeV}$. Using isospin conservation, we set the first upper limits on the photoproduction cross sections of the ${\pi }_1^0(1600)$ and ${\pi }_1^{-}(1600)$. We combine these limits with lattice calculations of decay widths and find that photoproduction of ${\eta }^{\prime }\pi$ is the most sensitive two-body system to search for the ${\pi }_1(1600)$.

We demonstrate an atom interferometer measurement protocol compatible with operation on a dynamic platform. Our method employs two open interferometers, derived from the same atomic source, with different interrogation times to eliminate initial velocity dependence while retaining precision, accuracy, and long term stability. We validate the protocol by measuring gravitational tides, achieving a precision of $4.5\mathrm{\mu }\mathrm{Gal}$ in 2000 runs (6.7 h), marking the first demonstration of inertial quantity measurement with open atom interferometry that achieves long-term phase stability.