Vortex-antivortex wavefunction of a degenerate quantum gas

A mechanism of a pinning of the quantized matter wave vortices by optical vortices in a specially arranged optical dipole traps is discussed. The vortex-antivortex optical arrays of rectangular symmetry are shown to transfer angular orbital momentum and form the "antiferromagnet"-like matter waves. The separable Hamiltonian for matter waves in pancake trapping geometry is proposed and 3D-wavefunction is factorized in a product of wavefunctions of the 1D harmonic oscillator and 2D vortex-antivortex quantum state. The 2D wavefunction's phase gradient field associated via Madelung transform with the field of classical velocities forms labyrinth-like structure. The macroscopic quantum state composed of periodically spaced counter-rotating BEC superfluid vortices has zero angular momentum and nonzero rotational energy.Comment: 11 pages, 5 figure

Surface functionalization of biomedical Ti-6Al-7Nb alloy by liquid metal dealloying

Surface functionalization is an effective approach to change the surface properties of a material to achieve a specific goal such as improving the biocompatibility of the material. Here, the surface of the commercial biomedical Ti-6Al-7Nb alloy was functionalized through synthesizing of a porous surface layer by liquid metal dealloying (LMD). During LMD, the Ti-6Al-7Nb alloy is immersed in liquid magnesium (Mg) and both materials react with each other. Particularly, aluminum (Al) is selectively dissolved from the Ti-6Al-7Nb alloy into liquid Mg while titanium (Ti) and niobium (Nb) diffuse along the metal/liquid interface to form a porous structure. We demonstrate that the porous surface layer in the Ti-6Al-7Nb alloy can be successfully tailored by LMD. Furthermore, the concentration of harmful Al in this porous layer is reduced by about 48% (from 5.62 ± 0.11 wt.% to 2.95 ± 0.05 wt.%) after 30 min of dealloying at 1150 K. The properties of the porous layer (e.g., layer thickness) can be tuned by varying the dealloying conditions. In-vitro tests suggest improved bone formation on the functionalized porous surface of the Ti-6Al-7Nb alloy. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.European Research Council, ERCTohoku UniversityMinistry of Science and Higher Education of the Russian FederationNanjing University of Science and Technology, NUST: K2-2020-020MA 3333/13-1Supervision, I.V.O., R.W.-R., L.Z., L.M., J.E. and H.K.; Validation, I.V.O., S.-H.J., and B.L.; Writing – original draft, I.V.O. and B.L.; Writing – review & editing, all. All authors have read and agreed to the published version Funding: The financial support was provided by the German Science Foundation under the Leibniz Program of the manuscript. (Grant MA 3333/13-1), by the European Research Council (ERC) under the ERC Advanced Grant INTELHYB (grant Funding: The financial support was provided by the German Science Foundation under the Leibniz Program Ministry of Science and Higher Education of the Russian Federation, in the framework of the Increase Competitiveness (Grant MA 3333/13-1), by the European Research Council (ERC) under the ERC Advanced Grant INTELHYB Program of NUST «MISiS» (grant number K2-2020-020). I.V.O. is grateful for the financial support provided by the International Collaboration Center, Institute for Materials Research (ICC-IMR), Tohoku University, Japan. 02.A03.21.0006), and the Ministry of Science and Higher Education of the Russian Federation, in the framework Conflicts of Interest: The authors declare no conflict of interest. of the Increase Competitiveness Program of NUST «MISiS» (grant number K2-2020-020). I.V.O. is grateful for the financial support provided by the International Collaboration Center, Institute for Materials Research (ICC-IMR), Tohoku University, Japan

Experimental observation of spontaneous spin polarization of electrons in hybridized states of transition element impurities in semiconductors

Experimental evidence of the possible existence of spontaneous spin polarization of the electron system in hybridized states formed by transition element impurity atoms in the conduction band of semiconducting crystals is examined. The details of a quantitative interpretation of experiments on the temperature dependence of the specific heat and elastic moduli of mercury selenide crystals with iron impurities confirm the feasibility of establishing the presence of electron spin polarization in this type of experiment, as well as the possible existence of polarization in the crystals studied here. Theoretical arguments support the observation of a thermodynamic anomalous Hall effect owing to spontaneously polarized donor electrons from low-concentration impurities. © 2013 AIP Publishing LLC

Quantum Billiards with Surface Scattering: Ballistic Sigma-Model Approach

Statistical properties of energy levels and eigenfunctions in a ballistic system with diffusive surface scattering are investigated. The two-level correlation function, the level number variance, the correlation function of wavefunction intensities, and the inverse participation ratio are calculated.Comment: 4 pages REVTEX, two figures included as eps file

Semi-classical Theory of Conductance and Noise in Open Chaotic Cavities

Conductance and shot noise of an open cavity with diffusive boundary scattering are calculated within the Boltzmann-Langevin approach. In particular, conductance contains a non-universal geometric contribution, originating from the presence of open contacts. Subsequently, universal expressions for multi-terminal conductance and noise valid for all chaotic cavities are obtained classically basing on the fact that the distribution function in the cavity depends only on energy and using the principle of minimal correlations.Comment: 4 pages, 1 .eps figur