Absolute cross sections for isotopically identified products formed in multinucleon transfer in the ${}^{136}\mathrm{Xe}+{}^{198}\mathrm{Pt}$ system at $\sim 8\mathrm{MeV}/\mathrm{nucleon}$ are reported. The isotopic distributions obtained using a large acceptance spectrometer demonstrated the production of the “hard-to-reach” neutron-rich isotopes for $Z<78$ around the $N=126$ shell closure far from stability. The main contribution to the formation of these exotic nuclei is shown to arise in collisions with a small kinetic energy dissipation. The present experimental finding corroborates for the first time recent predictions that multinucleon transfer reactions would be the optimum method to populate and characterize neutron-rich isotopes around $N=126$ which are crucial for understanding both astrophysically relevant processes and the evolution of “magic” numbers far from stability.

We investigate the semiclassical phase-space probability distribution $P(x,p)$ of cold atoms in a Sisyphus cooling lattice with an additional harmonic confinement. We pose the question of whether this nonequilibrium steady state satisfies the equivalence of energy and probability. This equivalence is the foundation of Boltzmann-Gibbs and generalized thermostatic statistics, and a prerequisite for the description in terms of a temperature. At large energies, $P(x,p)$ depends only on the Hamiltonian $H(x,p)$ and the answer to the question is yes. In distinction to the Boltzmann-Gibbs state, the large-energy tails are power laws $P(x,p)\propto H(x,p{)}^{-1/D}$, where $D$ is related to the depth of the optical lattice. At intermediate energies, however, $P(x,p)$ cannot be expressed as a function of the Hamiltonian and the equivalence between energy and probability breaks down. As a consequence the average potential and kinetic energy differ and no well-defined temperature can be assigned. The Boltzmann-Gibbs state is regained only in the limit of deep optical lattices. For strong confinement relative to the damping, we derive an explicit expression for the stationary phase-space distribution.

We theoretically investigate elastic waves propagating in metamaterials with simultaneous zero indices for both the longitudinal and transverse waves. With scattering objects (here cylinders) present in the metamaterial slabs, while the elastic waves can mostly transmit through the metamaterial slabs perfectly, exhibiting the well-known cloaking effect of zero-index metamaterials, they nevertheless become totally blocked at resonances, indicating strong elastic wave scattering by the objects in the cases. However, despite the occurrence of the elastic wave scattering, there is, counterintuitively, no mode conversion between the longitudinal and transverse waves in the process, completely in contrast to that in conventional elastic media. A design of a two-dimensional phononic crystal with these peculiar properties is presented.

The interplay between topological phases of matter and dissipative baths constitutes an emergent research topic with links to condensed matter, photonic crystals, cold atomic gases, and quantum information. While recent studies suggest that dissipative baths can induce topological phases in intrinsically trivial quantum materials, the backaction of topological invariants on dissipative baths is overlooked. By exploring this backaction for a centrosymmetric Dirac insulator coupled to phonons, we show that the linewidths of bulk optical phonons can reveal electronic band inversions. This result is the first known example where topological phases of an open quantum system may be detected by measuring the bulk properties of the surrounding environment.

Transparent conductors (TCs) combine the usually contraindicated properties of electrical conductivity with optical transparency and are generally made by starting with a transparent insulator and making it conductive via heavy doping, an approach that generally faces severe “doping bottlenecks.” We propose a different idea for TC design—starting with a metallic conductor and designing transparency by control of intrinsic interband transitions and intraband plasmonic frequency. We identify the specific design principles for three such prototypical intrinsic TC classes and then search computationally for materials that satisfy them. Remarkably, one of the intrinsic TC, ${\mathrm{Ag}}_3{\mathrm{Al}}_{22}{\mathrm{O}}_{34}$, is predicted also to be a prototype 3D compounds that manifest natural 2D electron gas regions with very high electron density and conductivity.

We report the first experimental demonstration of anomalous breakdown of the effective medium approximation in all-dielectric deeply subwavelength thickness ($d\sim \lambda /160-\lambda /30$) multilayers, as recently predicted theoretically [H. H. Sheinfux et al., Phys. Rev. Lett. 113, 243901 (2014)]. Multilayer stacks are composed of alternating alumina and titania layers fabricated using atomic layer deposition. For light incident on such multilayers at angles near the total internal reflection, we observe pronounced differences in the reflectance spectra for structures with 10- vs 20-nm thick layers, as well as for structures with different layers ordering, contrary to the predictions of the effective medium approximation. The reflectance difference can reach values up to 0.5, owing to the chosen geometrical configuration with an additional resonator layer employed for the enhancement of the effect. Our results are important for the development of new high-precision multilayer ellipsometry methods and schemes, as well as in a broad range of sensing applications.

We present how the surface-state correspondence, conjectured by Miyaji and Takayanagi, works in the setup of ${\mathrm{AdS}}_3/{\mathrm{CFT}}_2$ by generalizing the formulation of a continuous multiscale entanglement renormalization group ansatz. The boundary states in conformal field theories play a crucial role in our formulation and the bulk diffeomorphism is naturally taken into account. We give an identification of bulk local operators which reproduces correct scalar field solutions on ${\mathrm{AdS}}_3$ and bulk scalar propagators. We also calculate the information metric for a locally excited state and show that it reproduces the time slice of ${\mathrm{AdS}}_3$.

We show that, without any extra physical degree introduced, the standard model can be readily reformulated as a double field theory. Consequently, the standard model can couple to an arbitrary stringy gravitational background in an $\mathbf{O}(4,4)$ $T$-duality covariant manner and manifest two independent local Lorentz symmetries, $\mathbf{\text{Spin}}(1,3)\times \mathbf{\text{Spin}}(3,1)$. While the diagonal gauge fixing of the twofold spin groups leads to the conventional formulation on the flat Minkowskian background, the enhanced symmetry makes the standard model more rigid, and also stringy, than it appeared. The $CP$ violating $\theta$ term may no longer be allowed by the symmetry, and hence the strong $CP$ problem can be solved. There are now stronger constraints imposed on the possible higher order corrections. We speculate that the quarks and the leptons may belong to the two different spin classes.

In view of the recent diboson resonant excesses reported by both ATLAS and CMS Collaborations, we suggest that a new weak singlet pseudoscalar particle ${\eta }_{WZ}$ may decay into two weak bosons while being produced in gluon fusion at the LHC. The couplings to the gauge bosons can arise from a Wess-Zumino-Witten anomaly term and thus we study an effective model based on the anomaly term as a well motivated phenomenological model. In models where the pseudoscalar particle arises as a composite state, the coefficients of the anomalous couplings can be related to the fermion components of the underlying dynamics. We provide an example to test the feasibility of the idea.

We report the first measurement of the target single-spin asymmetry, $A_y$, in quasielastic scattering from the inclusive reaction ${{}^3\mathrm{He}}^{\uparrow }(e,e^{\prime })$ on a ${}^3\mathrm{He}$ gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero $A_y$ can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at $Q^2=0.13$, 0.46, and $0.97{\mathrm{GeV}}^2$. These measurements demonstrate, for the first time, that the ${}^3\mathrm{He}$ asymmetry is clearly nonzero and negative at the $4\sigma –9\sigma$ level. Using measured proton-to-${}^3\mathrm{He}$ cross-section ratios and the effective polarization approximation, neutron asymmetries of $-(1–3)\%$ were obtained. The neutron asymmetry at high $Q^2$ is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at $Q^2=0.97{\mathrm{GeV}}^2$ agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.

Ultrafast high harmonic beams provide new opportunities for coherently controlling excitation and ionization processes in atoms, molecules, and materials on attosecond time scales by employing multiphoton two-pathway electron-wave-packet quantum interferences. Here we use spectrally tailored and frequency tuned vacuum and extreme ultraviolet harmonic combs, together with two phase-locked infrared laser fields, to show how the total single and double photoionization yields of argon can be coherently modulated by controlling the relative phases of both optical and electronic-wave-packet quantum interferences. This Letter is the first to apply quantum control techniques to double photoionization, which is a fundamental process where a single, high-energy photon ionizes two electrons simultaneously from an atom.

The substitution of hydrogen (H) by deuterium (D) in ice $\mathrm{I}h$ and in its H-ordered version, ice XI, produces an anomalous form of volume isotope effect (VIE), i.e., volume expansion. This VIE contrasts with the normal VIE (volume contraction) predicted in ice-VIII and in its H-disordered form, ice VII. Here we investigate the VIE in ice XI and in ice VIII using first principles quasiharmonic calculations. We conclude that normal and anomalous VIEs can be produced in ice VIII and ice XI in sequence by application of pressure (ice XI starting at negative pressures) followed by a third type—anomalous VIE with zero-point volume contraction. The latter should also contribute to the isotope effect in the ice VII $\to$ ice X transition. The predicted change between normal and anomalous VIE in ice VIII at 14.3 GPa and 300 K is well reproduced experimentally in ice VII using x-ray diffraction measurements. The present discussion of the VIE is general, and conclusions should be applicable to other solid phases of ${\mathrm{H}}_2\mathrm{O}$, possibly to liquid water under pressure, and to other H-bonded materials.

The blackbody theory is revisited in the case of thermal electromagnetic fields inside uniaxial anisotropic media in thermal equilibrium with a heat bath. When these media are hyperbolic, we show that the spectral energy density of these fields radically differs from that predicted by Planck’s blackbody theory and that the maximum of the spectral energy density determined by Wien’s law is redshifted. Finally, we derive the Stefan-Boltzmann law for hyperbolic media which becomes a quadratic function of the heat bath temperature.

We extend the applicability range of fermionic path integral Monte Carlo simulations to heavier elements and lower temperatures by introducing various localized nodal surfaces. Hartree-Fock nodes yield the most accurate prediction for pressure and internal energy, which we combine with the results from density functional molecular dynamics simulations to obtain a consistent equation of state for hot, dense silicon under plasma conditions and in the regime of warm dense matter ($2.3–18.6\mathrm{g}{\mathrm{cm}}^{-3}$, $5.0\times 10^5-1.3\times 10^8\mathrm{K}$). The shock Hugoniot curve is derived and the structure of the fluid is characterized with various pair correlation functions.

In terms of the Bogoliubov–de Gennes approach, we investigate the Majorana bound state (MBS) in a vortex of proximity-induced superconductivity on the surface of a topological insulator. Mapping out the local density of states (LDOS) of quasiparticle excitations as a function of energy and distance from the vortex center, it is found that the spectral distribution evolves from a $V$ shape to a $Y$ shape with the emergence of a MBS upon variation of the chemical potential, consistent with the STM/STS measurement in a very recent experiment [Xu et al., Phys. Rev. Lett. 114, 017001 (2015)] on a ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ thin layer on the top of ${\mathrm{NbSe}}_2$. Moreover, we demonstrate that there is a checkerboard-type pattern in the relative LDOS between the spin-up and -down channels, where the quantum mechanical wave function of the MBS manifests itself clearly as a single quantum state. Therefore, a spin-resolved STM/STS technique is expected to be able to provide phase-sensitive evidence for a MBS in the vortex core of a topological superconductor.

We show that a class of exactly solvable quantum Ising models, including the transverse-field Ising model and anisotropic $XY$ model, can be characterized as the loops in a two-dimensional auxiliary space. The transverse-field Ising model corresponds to a circle and the $XY$ model corresponds to an ellipse, while other models yield cardioid, limacon, hypocycloid, and Lissajous curves etc. It is shown that the variation of the ground state energy density, which is a function of the loop, experiences a nonanalytical point when the winding number of the corresponding loop changes. The winding number can serve as a topological quantum number of the quantum phases in the extended quantum Ising model, which sheds some light upon the relation between quantum phase transition and the geometrical order parameter characterizing the phase diagram.

Three-dimensional (3D) variants of the Kitaev model can harbor gapless spin liquids with a Majorana Fermi surface on certain tricoordinated lattice structures such as the recently introduced hyperoctagon lattice. Here, we investigate Fermi surface instabilities arising from additional spin exchange terms (such as a Heisenberg coupling) which introduce interactions between the emergent Majorana fermion degrees of freedom. We show that independent of the sign and structure of the interactions, the Majorana surface is always unstable. Generically, the system spontaneously doubles its unit cell at exponentially small temperatures and forms a spin liquid with line nodes. Depending on the microscopics, further symmetries of the system can be broken at this transition. These spin-Peierls instabilities of a 3D spin liquid are closely related to BCS instabilities of fermions.