Tensor effects on gap evolution of N=40 from non-relativistic and relativistic mean-field theory

Tensor effects on the N=40 gap evolution of N=40 isotones are studied by employing the Skyrme-Hartree-Fock-Bogoliubov (SHFB) and relativistic Hartree-Fock-Bogoliubov (RHFB) theories. The results with and without the inclusion of the tensor component are compared with the experimental data. When the tensor force is included, both of the two different approaches are found to give the same trend and agree with the experimental one, which indicates the necessity of introducing the tensor force in the evolution of N=40 subshell and on the other hand the reliability of the methods. Furthermore, it is shown that the gap evolution is primarily determined by the corresponding tensor contributions from $\pi$ and $\rho$-tensor coupling in the relativistic framework.Comment: 4 pages, 3 figure

Valley controlled propagation of pseudospin states in bulk metacrystal waveguides

Light manipulations such as spin-direction locking propagation, robust transport, quantum teleportation and reconfigurable electromagnetic pathways have been investigated at the boundaries of photonic systems. Recently by breaking Dirac cones in time-reversal invariant photonic crystals, valley-pseudospin coupled edge states have been employed to realize selective propagation of light. Here, without photonic boundaries, we realize the propagation of pseudospin states in three-dimensional bulk metacrystal waveguides by employing the ubiquitous valley degree of freedom. Valley-dependent pseudospin bands are achieved in three-dimensional metacrystal waveguides without Dirac cones. Reconfigurable photonic valley Hall effect is proposed after studying the variation of pseudospin states near K' and K valleys. Moreover, a prototype of photonic blocker is realized by cascading two inversion asymmetric metacrystal waveguides in which the pseudospin direction locking propagation exists. In addition, valley-dependent pseudospin bands are also discussed in a realistic metamaterials sample. These results show an alternative way towards molding the pseudospin flow in photonic systems.Comment: 26 pages, 7 figure

Transverse angular momentum in topological photonic crystals

Engineering local angular momentum of structured light fields in real space enables unprecedented applications in many fields, in particular for the realization of unidirectional robust transport in topological photonic crystals with non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin or orbital angular momentum, robust light flow propagating along opposite directions was observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating-sign topological charge was found at the boundary of such two photonic crystals. In addition, we also found that unidirectional transport is robust to the working frequency even when the ring-size or location of pseudo-spin source varies in a certain range, leading to the superiority of broadband photonic device. These findings enable for making use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in telecom region and other potential applications in integrated photonic circuits such as on-chip robust delay line.Comment: 17 pages, 5 figure

Layered Photonic Topological Insulators

The recent realization of photonic topological insulators has brought the discovery of fundamentally new states of light and revolutionary applications such as non-reciprocal devices for photonic diodes and robust waveguides for light routing. The spatially distinguished layer pseudospin has attracted attention in two-dimensional electronic materials. Here we report layered photonic topological insulators based on all-dielectric bilayer photonic crystal slabs. The introduction of layer pseudospin offers more dispersion engineering capability, leading to the layer-polarized and layer-mixed photonic topological insulators. Their phase transition is demonstrated with a model Hamiltonian by considering the nonzero interlayer coupling. Layer-direction locking behavior is found in layer-polarized photonic topological insulators. High transmission is preserved in the bilayer domain wall between two layer-mixed photonic topological insulators, even when a large defect is introduced. Layered photonic topological insulators not only offer a route towards the observation of richer nontrivial phases, but also open a way for device applications in integrated photonics and information processing by using the additional layer pseudospin.Comment: 16 pages, 5 figure

New Generalization of Perturbed Ostrowski Type Inequalities and Applications

Generalizations of Ostrowski type inequality for functions of Lipschitzian type are established. Applications in numerical integration and cumulative distribution functions are also given.Comment: 11 pages

Valley-protected backscattering suppression in silicon photonic graphene

In this paper, we study valley degree of freedom in all dielectric silicon photonic graphene. Photonic band gap opening physics under inversion symmetry breaking is revisited by the viewpoint of nonzero valley Chern number. Bulk valley modes with opposite orbital angular momentum are unveiled by inspecting time-varying electric fields. Topological transition is well illustrated through photonic Dirac Hamiltonian. Valley dependent edge states and the associated valley-protected backscattering suppression around Z-shape bend waveguide have been demonstrated.Comment: 12 pages, 4 figure

Proton radioactivity described by covariant density functional theory with Similarity Renormalization Group method

Half-life of proton radioactivity of spherical proton emitters is studied within the scheme of covariant density functional (CDF) theory, and for the first time the potential barrier that prevents the emitted proton is extracted with the similarity renormalization group (SRG) method, in which the spin-orbit potential along with the others that turn out to be non-negligible can be derived automatically. The spectroscopic factor that is significant is also extracted from the CDF calculations. The estimated half-lives are found in good agreement with the experimental values, which not only confirms the validity of the CDF theory in describing the proton-rich nuclei, but also indicates the prediction power of present approach to calculate the half-lives and in turn to extract the structural information of proton emitters.Comment: 6 pages, 2 figure

Feasibility of underwater free space quantum key distribution

We investigate the optical absorption and scattering properties of underwater media pertinent to our underwater free space quantum key distribution (QKD) channel model. With the vector radiative transfer theory and Monte Carlo method, we obtain the attenuation of photons, the fidelity of the scattered photons, the quantum bit error rate and the sifted key generation rate of underwater quantum communication. It can be observed from our simulations that the most secure single photon underwater free space QKD is feasible in the clearest ocean water.Comment: 12 pages, 10 figure

Odd-even staggerings on nuclear binding energy described by the covariant density functional theory

The odd-even staggerings (OES) on nuclear binding energies are studied systematically within the covariant density functional (CDF) theories, specifically the relativistic Hartree-Fock-Bogoliubov (RHFB) and the relativistic Hartree-Bogoliubov (RHB) theories. Taking the finite-range Gogny force D1S as an effective pairing interaction, both CDF models can provide appropriate descriptions on the OESs of nuclear binding energies for C, O, Ca, Ni, Zr, Sn, Ce, Gd and Pb isotopes as well as for N=50 and 82 isotones. However, due to the inconsistence between the non-relativistic pairing interaction and the relativistic effective Lagrangians, there exist some systematical discrepancies from the data, i.e., the underestimated OESs in light C and O isotopes and the overestimated ones in heavy region, respectively. Such discrepancies can be eliminated partially by introducing a $Z$- or $N$-dependent strength factor into the pairing force Gogny D1S. In addition, successful descriptions of the occupation numbers of Sn isotopes are achieved with the optimized Gogny pairing force. Furthermore, the analysis of the systematics of both pairing effects and nuclear binding energy indicate the requirement of an unified relativistic mechanism in both p-p and p-h channels to improve the quantitative precision of the theory.Comment: 10pages, 6 figures, 4 table

Anisotropy-induced Fano resonance

An optical Fano resonance, which is caused by birefringence control rather than frequency selection, is discovered. Such birefringence-induced Fano resonance comes with fast-switching radiation. The resonance condition $\varepsilon_t< 1/\varepsilon_r$ is revealed and a tiny perturbation in birefringence is found to result in a giant switch in the principal light pole induced near surface plasmon resonance. The loss and size effects upon the Fano resonance have been studied Fano resonance is still pronounced, even if the loss and size of the object increase. The evolutions of the radiation patterns and energy singularities illustrate clearly the sensitive dependence of Fano resonance upon the birefringence