A high-quality single crystal of uranium ditelluride with a critical temperature of 21K is used to study the superconducting phase diagram (SC) under magnetic fields (H) along the hard magnetic b-axis. Measurements of simultaneous electrical resistivity and alternating current magnetic susceptibility reveal the presence of low-field superconductive (LFSC) and high-field superconductive (HFSC) phases, exhibiting distinct angular dependences in applied fields. Improved crystal quality bolsters the upper critical field in the LFSC phase, yet the H^* of 15T, where the HFSC phase manifests, remains uniform across different crystals. The LFSC phase, near H^*, exhibits a phase boundary signature, revealing an intermediate superconducting phase with minimal pinning forces for flux.

A particularly exotic type of quantum spin liquid, fracton phases, are characterized by elementary quasiparticles that are inherently immobile. The unconventional gauge theories, specifically tensor and multipolar gauge theories, describe the phases; these phases are characteristic, respectively, of type-I or type-II fracton phases. Singular patterns in the spin structure factor, including multifold pinch points for type-I and quadratic pinch points for type-II fracton phases, have been linked to both variants. In a numerical analysis of the octahedral lattice's spin S=1/2 quantum model, which features exact multifold and quadratic pinch points and a distinctive pinch line singularity, we determine how quantum fluctuations affect these observed patterns. Pseudofermion and pseudo-Majorana functional renormalization group calculations on a large scale indicate that the stability of fracton phases is correlated with the preservation of their spectroscopic signatures. Quantum fluctuations, across all three instances, engender a substantial modification of pinch point or line shapes, inducing a smearing effect and diverting signals from singularities, in contrast to the effects exclusively attributed to thermal fluctuations. The outcome underscores a potential for brittleness in these phases, hence facilitating the detection of distinctive signatures of their fragments.

Precision measurement and sensing have long sought to achieve narrow linewidths. We posit a parity-time symmetric (PT-symmetric) feedback approach for the purpose of decreasing the resonance linewidths of systems. Through the implementation of a quadrature measurement-feedback loop, a dissipative resonance system is rendered a PT-symmetric system. Departing from the typical structure of PT-symmetric systems, which generally employ two or more modes, the PT-symmetric feedback system presented here leverages a singular resonance mode, resulting in an expanded spectrum of applications. The method provides a considerable improvement in linewidth narrowing and enhanced measurement sensitivity. A thermal atom ensemble demonstrates the concept, leading to a 48-fold reduction in magnetic resonance linewidth. Implementing magnetometry procedures resulted in a 22-fold enhancement of the measurement's sensitivity. This project provides a pathway for the investigation of non-Hermitian physics and precise measurements within feedback-equipped resonance systems.

The spatially varying Weyl-node positions within a Weyl-semimetal superstructure are predicted to cause a novel metallic state of matter to emerge. The new state exhibits anisotropic, extended Fermi surfaces, conceptually built from the stretching of Weyl nodes into Fermi arc-like states. The chiral anomaly of the parental Weyl semimetal is displayed by this Fermi-arc metal. immuno-modulatory agents However, the Fermi-arc metal exhibits an ultraquantum state with an anomalous chiral Landau level as the exclusive state at the Fermi energy, reaching this state within a finite energy window at zero magnetic field, distinct from its parental Weyl semimetal counterpart. A universal low-field ballistic magnetoconductance, concomitant with the absence of quantum oscillations, is an outcome of the ultraquantum state, effectively obscuring the Fermi surface from detection by de Haas-van Alphen and Shubnikov-de Haas measurements, despite its influence on other response characteristics.

We unveil the first experimental measurement of the angular correlation phenomenon in the Gamow-Teller ^+ decay of ^8B. By leveraging the Beta-decay Paul Trap, we accomplished this, advancing our prior investigations into the ^- decay of ^8Li. In accordance with the V-A electroweak interaction within the standard model, the ^8B finding places a limit on the exotic right-handed tensor current, specifically restricting its ratio to the axial-vector current to a value less than 0.013 at the 95.5% confidence level. Due to the application of an ion trap, the first high-precision angular correlation measurements in mirror decays have been realized. The fusion of our ^8Li results with the ^8B data offers a fresh path towards heightened precision in the exploration of exotic currents.

Numerous interconnected units are a key component of associative memory algorithms. The Hopfield model, a quintessential example, has seen its quantum counterparts primarily developed through the application of open quantum Ising models. learn more Capitalizing on the infinite degrees of freedom in phase space of a single driven-dissipative quantum oscillator, we propose an implementation of associative memory. In a broad context, the model augments the storage capacity of discrete neuron-based systems. We validate the ability to discriminate successfully between n coherent states, which exemplify the stored patterns. Continual modification of the driving strength allows for continuous adjustments to these parameters, thus altering the learning rule. The existence of a spectral separation in the Liouvillian superoperator proves essential to the associative memory's function. This separation gives rise to a substantial difference in timescale for the dynamics, showcasing a metastable phase.

Despite the impressive phase-space density of over 10^-6 achieved through direct laser cooling of molecules in optical traps, the number of molecules remains small. A mechanism that merges sub-Doppler cooling and magneto-optical trapping would be vital for achieving near-perfect transfer of ultracold molecules from a magneto-optical trap (MOT) to a conservative optical trap, enabling the progress towards quantum degeneracy. Employing the distinctive energy configuration of YO molecules, we present the inaugural blue-detuned MOT for molecules, meticulously optimized for both gray-molasses sub-Doppler cooling and robust trapping forces. This inaugural sub-Doppler molecular magneto-optical trap exhibits an improvement of two orders of magnitude in phase-space density, outperforming all previous molecular magneto-optical trap implementations.

Through the application of a novel isochronous mass spectrometry method, the masses of ^62Ge, ^64As, ^66Se, and ^70Kr were measured for the first time, while improved accuracy was achieved in the redetermination of the masses of ^58Zn, ^61Ga, ^63Ge, ^65As, ^67Se, ^71Kr, and ^75Sr. Residual proton-neutron interactions (V pn), derivable from the novel mass data, are observed to decrease (increase) with increasing mass A in even-even (odd-odd) nuclei, beyond Z=28. Replicating the bifurcation of V pn with existing mass models is impossible, nor does it accord with predicted pseudo-SU(4) symmetry restoration within the fp shell. Ab initio calculations, utilizing a chiral three-nucleon force (3NF), showed an increase in T=1 pn pairing over T=0 pn pairing in this mass region. This is reflected in contrasting evolutionary patterns for V pn in even-even and odd-odd nuclei.

Nonclassical quantum states serve as a defining characteristic, separating quantum systems from their classical counterparts. Consistently generating and manipulating quantum states within a macroscopic spin system continues to be a considerable experimental obstacle. This experiment demonstrates the quantum control of an individual magnon in a sizeable spin system (a 1 mm-diameter yttrium-iron-garnet sphere), linked to a superconducting qubit through a microwave cavity. Via in-situ tuning of the qubit frequency using the Autler-Townes effect, we manipulate this single magnon, generating its nonclassical quantum states, including the single-magnon state and the superposition with the vacuum (zero magnon) state. Furthermore, we validate the deterministic creation of these unconventional states using Wigner tomography. This experiment, involving a macroscopic spin system, has yielded the first reported deterministic generation of nonclassical quantum states, setting the stage for exploring their potential applications in quantum engineering.

Glasses deposited via vaporization onto a chilled substrate show a significantly greater degree of thermodynamic and kinetic stability than typical glasses. Molecular dynamics simulations are applied to the vapor deposition of a model glass-forming substance, revealing the sources of its elevated stability relative to conventional glasses. cannulated medical devices The stability of vapor-deposited glass is tied to the presence of locally favored structures (LFSs), reaching a maximum at the optimal deposition temperature. Surface relaxation dynamics appear to be crucial to the enhanced LFS formation near the free surface, hence supporting the theory that vapor-deposited glasses' stability is contingent upon these dynamics.

The application of lattice QCD methods is extended to the second-order, two-photon-mediated, rare decay of an electron-positron pair. The complex decay amplitude, as described by this decay, can be calculated directly from the underlying theories of quantum chromodynamics (QCD) and quantum electrodynamics (QED) by utilizing combined Minkowski and Euclidean space techniques. The leading connected and disconnected diagrams are given consideration; a continuum limit is evaluated and an estimation of the systematic errors is made. The real part of ReA is determined to be 1860(119)(105)eV, and the imaginary part ImA is 3259(150)(165)eV. This yields a more accurate ratio ReA/ImA of 0571(10)(4) and a partial width ^0 equal to 660(061)(067)eV. The first errors are characterized by statistical variability, whereas the subsequent errors are demonstrably systematic.