The properties of pygmy dipole states in ${}^{208}\mathrm{Pb}$ were investigated using the ${}^{208}\mathrm{Pb}$(${}^{17}\mathrm{O}$, ${}^{17}\mathrm{O}’\gamma$) reaction at 340 MeV and measuring the $\gamma$ decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted $\gamma$ rays and of the scattered particles were measured. The results are compared with ($\gamma$, ${\gamma }^{\prime }$) and ($p$, $p^{\prime }$) data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the $2^{+}$ and $3^{-}$ states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the $1^{-}$ excited states from 4 to 8 MeV.

We present the first realization of a solitonic atom interferometer. A Bose-Einstein condensate of $1\times {10}^4$ atoms of rubidium-85 is loaded into a horizontal optical waveguide. Through the use of a Feshbach resonance, the $s$-wave scattering length of the ${}^{85}\mathrm{Rb}$ atoms is tuned to a small negative value. This attractive atomic interaction then balances the inherent matter-wave dispersion, creating a bright solitonic matter wave. A Mach-Zehnder interferometer is constructed by driving Bragg transitions with the use of an optical lattice colinear with the waveguide. Matter-wave propagation and interferometric fringe visibility are compared across a range of $s$-wave scattering values including repulsive, attractive and noninteracting values. The solitonic matter wave is found to significantly increase fringe visibility even compared with a noninteracting cloud.

A dewetting viscous film develops a characteristic fluid rim at its receding edge due to mass conservation. In the course of the dewetting process, the rim becomes unstable via an instability of Rayleigh-Plateau type. An important difference exists between this classic instability of a liquid column and the rim instability in a thin film as the growth of the rim is continuously fueled by the receding film. We explain how the development and macroscopic morphology of the rim instability are controlled by the slip of the film on the substrate. A single thin-film model captures quantitatively the characteristics of the complete evolution of the rim observed in the experiments.

We demonstrate that charged particles in a sufficiently intense standing wave are compressed toward, and oscillate synchronously at, the antinodes of the electric field. We call this unusual behavior anomalous radiative trapping (ART). We show using dipole pulses, which offer a path to increased laser intensity, that ART opens up new possibilities for the generation of radiation and particle beams, both of which are high energy, directed, and collimated. ART also provides a mechanism for particle control in high-intensity quantum-electrodynamics experiments.

We study the integrable model of one-dimensional bosons with contact repulsion. In the limit of weak interaction, we use the microscopic hydrodynamic theory to obtain the excitation spectrum. The statistics of quasiparticles changes with the increase of momentum. At lowest momenta good quasiparticles are fermions, while at higher momenta they are Bogoliubov bosons, in accordance with recent studies. In the limit of strong interaction, we analyze the exact solution and find exact results for the spectrum in terms of the asymptotic series. Those results undoubtedly suggest that fermionic quasiparticle excitations actually exist at all momenta for moderate and strong interaction and also at lowest momenta for arbitrary interaction. Moreover, at strong interaction we find highly accurate analytical results for several relevant quantities of the Lieb-Liniger model.

We show that a weak hexagonal periodic potential can transform a two-dimensional electron gas with an even-denominator magnetic filling factor into an quantum anomalous hall insulator of composite fermions, giving rise to the fractionally quantized Hall effect. The system provides a realization of the Haldane honeycomb-net model, albeit in a composite fermion system. We further propose a trial wave function for the state, and numerically evaluate its relative stability against the competing Hofstadter state. Possible sets of experimental parameters are proposed.

In this Letter, we present NMR spin-lattice and relaxometry data for proton transfer in one of the shortest known $\mathrm{N}-\mathrm{H}\cdots \mathrm{O}$ hydrogen bonds in a single crystal of 3,5 pyridinedicarboxylic acid (35PDCA). It is widely believed that proton transfer by quantum tunneling does not occur in short hydrogen bonds since the ground state energy level lies above the potential barrier, yet these data show a temperature independent, proton tunneling rate below 77 K and a clear deviation from classical dynamics below 91 K. This study therefore suggests that proton tunneling occurs in all hydrogen bonds at low temperature and the crossover temperature to classical hopping must be determined when evaluating whether proton tunneling persists at higher temperature, for example in enzyme catalysis under physiological conditions.

We demonstrate an all-optical magnetometer capable of measuring the magnitude and direction of a magnetic field using nonlinear magneto-optical rotation in cesium vapor. Vector capability is added by effective modulation of the field along orthogonal axes and subsequent demodulation of the magnetic-resonance frequency. This modulation is provided by the ac Stark shift induced by circularly polarized laser beams. The sensor exhibits a demonstrated rms noise floor of $\sim 65\mathrm{fT}/\sqrt{\mathrm{Hz}}$ in measurement of the field magnitude and $0.5\mathrm{mrad}/\sqrt{\mathrm{Hz}}$ in the field direction; elimination of technical noise would improve these sensitivities to $12\mathrm{fT}/\sqrt{\mathrm{Hz}}$ and $10\mu \mathrm{rad}/\sqrt{\mathrm{Hz}}$, respectively. Applications for this all-optical vector magnetometer would include magnetically sensitive fundamental physics experiments, such as the search for a permanent electric dipole moment of the neutron.

Quantum repeaters (QRs) provide a way of enabling long distance quantum communication by establishing entangled qubits between remote locations. In this Letter, we investigate a new approach to QRs in which quantum information can be faithfully transmitted via a noisy channel without the use of long distance teleportation, thus eliminating the need to establish remote entangled links. Our approach makes use of small encoding blocks to fault-tolerantly correct both operational and photon loss errors. We describe a way to optimize the resource requirement for these QRs with the aim of the generation of a secure key. Numerical calculations indicate that the number of quantum memory bits at each repeater station required for the generation of one secure key has favorable polylogarithmic scaling with the distance across which the communication is desired.

We investigate stable glassy states that are found when glass-forming liquids are biased to lower than average dynamical activity. By pinning the positions of randomly chosen particles, we show that many-body correlations in these states are relatively strong and long ranged compared to equilibrium reference states. The presence of strong many-body correlations in these apparently disordered systems supports the idea that stable glassy states exhibit a kind of “amorphous order,” which helps to explain their stability.

The most general action for a scalar field coupled to gravity that leads to second-order field equations for both the metric and the scalar—Horndeski’s theory—is considered, with the extra assumption that the scalar satisfies shift symmetry. We show that in such theories, the scalar field is forced to have a nontrivial configuration in black hole spacetimes, unless one carefully tunes away a linear coupling with the Gauss-Bonnet invariant. Hence, black holes for generic theories in this class will have hair. This contradicts a recent no-hair theorem which seems to have overlooked the presence of this coupling.

The BICEP2 Collaboration reports a detection of primordial cosmic microwave background (CMB) $B$ mode with a tensor-to-scalar ratio $r=0.20_{-0.05}^{+0.07}$ (68% C.L.). However, this result disagrees with the recent Planck limit $r<0.11$ (95% C.L.) on constraining inflation models. In this Letter we consider an inflationary cosmology with a preceding nonsingular bounce, which gives rise to observable signatures on primordial perturbations. One interesting phenomenon is that both the primordial scalar and tensor modes can have a step feature on their power spectra, which nicely cancels the tensor excess power on the CMB temperature power spectrum. By performing a global analysis, we obtain the 68% C.L. constraints on the parameters of the model from the $\text{Planck}+\mathrm{WP}$ and BICEP2 data together: the jump scale ${\log }_{10}(k_{\mathrm{B}}/{\mathrm{Mpc}}^{-1})=-2.4\pm 0.2$ and the spectrum amplitude ratio of bounce to inflation $r_B\equiv P_{\mathrm{m}}/A_{\mathrm{s}}=0.71\pm 0.09$. Our result reveals that the bounce inflation scenario can simultaneously explain the Planck and BICEP2 observations better than the standard cold dark matter model with a cosmological constant, and can be verified by future CMB polarization measurements.

The accurate evaluation of molecular properties lies at the core of predictive physical models. Most reliable quantum-chemical calculations are limited to smaller molecular systems while purely empirical approaches are limited in accuracy and reliability. A promising approach is to employ a quantum-mechanical formalism with simplifications and to compensate for the latter with parametrization. We propose a strategy of directly predicting the uncertainty interval for a property of interest, based on training‐data uncertainties, which sidesteps the need for an optimum set of parameters.

A rigorous QED evaluation of the two-photon exchange corrections to the $g$ factor of lithiumlike ions is presented. The screened self-energy corrections are calculated for the intermediate-$Z$ region, and its accuracy for the high-$Z$ region is essentially improved in comparison with that of previous calculations. As a result, the theoretical accuracy of the $g$ factor of lithiumlike ions is significantly increased. The theoretical prediction obtained for the $g$ factor of ${{}^{28}\mathrm{Si}}^{11+}$ $g_{\text{th}}=2.000889892(8)$ is in an excellent agreement with the corresponding experimental value $g_{\exp }=2.0008898899(21)$ [A. Wagner et al., Phys. Rev. Lett. 110, 033003 (2013)].