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This Letter extends the optical imaging from three- to four-dimensional information, which has an important scientific significance in both fundamental research and applied science.In the QCD axion dark matter scenario with postinflationary Peccei-Quinn symmetry breaking, the number density of axions, and hence the dark matter density, depends on the length of string per unit volume at cosmic time t, by convention written ζ/t^2. The expectation has been that the dimensionless parameter ζ tends to a constant ζ_0, a feature of a string network known as scaling. It has recently been claimed that in larger numerical simulations ζ shows a logarithmic increase with time, while theoretical modeling suggests an inverse logarithmic correction. Either case would result in a large enhancement of the string density at the QCD transition, and a substantial revision to the axion mass required for the axion to constitute all of the dark matter. With a set of new simulations of global strings, we compare the standard scaling (constant-ζ) model to the logarithmic growth and inverse-logarithmic correction models. In the standard scaling model, by fitting to linear growth in the mean string separation ξ=t/sqrt[ζ], we find ζ_0=1.19±0.20. We conclude that the apparent corrections to ζ are artifacts of the initial conditions, rather than a property of the scaling network. The residuals from the constant-ζ (linear ξ) fit also show no evidence for logarithmic growth, restoring confidence that numerical simulations can be simply extrapolated from the Peccei-Quinn symmetry-breaking scale to the QCD scale. Reanalysis of previous work on the axion number density suggests that recent estimates of the axion dark matter mass in the postinflationary symmetry-breaking scenario we study should be increased by about 50%.The temperature dependencies of the lower critical field H_c1(T) of several filled-skutterudite superconductors were investigated by local magnetization measurements. While LaOs_4As_12 and PrRu_4As_12 exhibit the H_c1(T) dependencies consistent with the single-band BCS prediction, for LaRu_4As_12 (the superconducting temperature T_c=10.4  K) with a similar three-dimensional Fermi surface, we observe a sudden increase in H_c1(T) deep in a superconducting state below about 0.32T_c. Remarkably, a rapid rise of H_c1(T) at approximately the same reduced temperature 0.27T_c is also found for the heavy-fermion compound PrOs_4Sb_12 (T_c≃1.78  K), in fair accord with the earlier macroscopic study. We attribute the unusual H_c1(T) dependencies of LaRu_4As_12 and PrOs_4Sb_12 to a kink structure in their superfluid densities due to different contributions from two nearly decoupled bands. Whereas LaRu_4As_12 is established as a two-band isotropic s-wave superconductor, nonsaturating behavior of H_c1(T) is observed for PrOs_4Sb_12, indicative of an anisotropic structure of a smaller gap. For this superconductor with broken time-reversal symmetry, our findings suggest a superconducting state with multiple symmetries of the order parameters.Quantum error correction is expected to be essential in large-scale quantum technologies. However, the substantial overhead of qubits it requires is thought to greatly limit its utility in smaller, near-term devices. Here we introduce a new family of special-purpose quantum error-correcting codes that offer an exponential reduction in overhead compared to the usual repetition code. 8-Cyclopentyl-1,3-dimethylxanthine They are tailored for a common and important source of decoherence in current experiments, whereby a register of qubits is subject to phase noise through coupling to a common fluctuator, such as a resonator or a spin defect. The smallest instance encodes one logical qubit into two physical qubits, and corrects decoherence to leading-order using a constant number of one- and two-qubit operations. More generally, while the repetition code on n qubits corrects errors to order t^O(n), with t the time between recoveries, our codes correct to order t^O(2^n). Moreover, they are robust to model imperfections in small- and intermediate-scale devices, where they already provide substantial gains in error suppression. As a result, these hardware-efficient codes open a potential avenue for useful quantum error correction in near-term, pre-fault tolerant devices.Nanoscale silica-silica contacts were recently found to exhibit logarithmic aging for times ranging from 0.1 to 100 s, consistent with the macroscopic rate and state friction laws and several other aging processes. Nanoscale aging in this system is attributed to progressive formation of interfacial siloxane bonds between surface silanol groups. However, understanding or even data for contact behavior for aging times less then 0.1  s, before the onset of logarithmic aging, is limited. Using a combination of atomic force microscopy experiments and kinetic Monte Carlo simulations, we find that aging is nearly linear with aging time at short timescales between ∼ 5 and 90 ms. We demonstrate that aging at these timescales requires the existence of a particular range of reaction energy barriers for interfacial bonding. Specifically, linear aging behavior consistent with experiments requires a narrow peak close to the upper bound of this range of barriers. These new insights into the reaction kinetics of interfacial bonding in nanoscale aging advance the development of physically based rate and state friction laws for nanoscale contacts.The ^7H system was populated in the ^2H(^8He,^3He)^7H reaction with a 26 AMeV ^8He beam. The ^7H missing mass energy spectrum, the ^3H energy and angular distributions in the ^7H decay frame were reconstructed. The ^7H missing mass spectrum shows a peak, which can be interpreted either as unresolved 5/2^+ and 3/2^+ doublet or one of these states at 6.5(5) MeV. The data also provide indications of the 1/2^+ ground state of ^7H located at 1.8(5) MeV with quite a low population cross section of ∼25  μb/sr within angular range θ_c.m.≃(17°-27°).