3,627 research outputs found

    Transport properties of a 3D topological insulator based on a strained high mobility HgTe film

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    We investigated the magnetotransport properties of strained, 80nm thick HgTe layers featuring a high mobility of mu =4x10^5 cm^2/Vs. By means of a top gate the Fermi-energy is tuned from the valence band through the Dirac type surface states into the conduction band. Magnetotransport measurements allow to disentangle the different contributions of conduction band electrons, holes and Dirac electrons to the conductivity. The results are are in line with previous claims that strained HgTe is a topological insulator with a bulk gap of ~15meV and gapless surface states.Comment: 11 pages (4 pages of main text, 6 pages of supplemental materials), 8 figure

    Electric dipole moment of the electron in YbF molecule

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    Ab initio calculation of the hyperfine, P-odd, and P,T-odd constants for the YbF molecule was performed with the help of the recently developed technique, which allows to take into account correlations and polarization in the outercore region. The ground state electronic wave function of the YbF molecule is found with the help of the Relativistic Effective Core Potential method followed by the restoration of molecular four-component spinors in the core region of ytterbium in the framework of a non-variational procedure. Core polarization effects are included with the help of the atomic Many Body Perturbation Theory for Yb atom. For the isotropic hyperfine constant A, accuracy of our calculation is about 3% as compared to the experimental datum. The dipole constant Ad (which is much smaller in magnitude), though better than in all previous calculations, is still underestimated by almost 23%. Being corrected within a semiempirical approach for a perturbation of 4f-shell in the core of Yb due to the bond making, this error is reduced to 8%. Our value for the effective electric field on the unpaired electron is 4.9 a.u.=2.5E+10 V/cm.Comment: 7 pages, REVTE

    Enhancement of the electric dipole moment of the electron in PbO

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    The a(1) state of PbO can be used to measure the electric dipole moment of the electron d_e. We discuss a semiempirical model for this state, which yields an estimate of the effective electric field on the valence electrons in PbO. Our final result is an upper limit on the measurable energy shift, which is significantly larger than was anticipated earlier: 2∣Wd∣de≥2.4×1025Hz[deecm] 2|W_d|d_e \ge 2.4\times 10^{25} \textrm{Hz} [ \frac{d_e}{e \textrm{cm}} ].Comment: 4 pages, revtex4, no figures, submitted to PR

    Using Molecules to Measure Nuclear Spin-Dependent Parity Violation

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    Nuclear spin-dependent parity violation arises from weak interactions between electrons and nucleons, and from nuclear anapole moments. We outline a method to measure such effects, using a Stark-interference technique to determine the mixing between opposite-parity rotational/hyperfine levels of ground-state molecules. The technique is applicable to nuclei over a wide range of atomic number, in diatomic species that are theoretically tractable for interpretation. This should provide data on anapole moments of many nuclei, and on previously unmeasured neutral weak couplings

    Enhancement of the electric dipole moment of the electron in BaF molecule

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    We report results of ab initio calculation of the spin-rotational Hamiltonian parameters including P- and P,T-odd terms for the BaF molecule. The ground state wave function of BaF molecule is found with the help of the Relativistic Effective Core Potential method followed by the restoration of molecular four-component spinors in the core region of barium in the framework of a non-variational procedure. Core polarization effects are included with the help of the atomic Many Body Perturbation Theory for Barium atom. For the hyperfine constants the accuracy of this method is about 5-10%.Comment: 8 pages, REVTEX, report at II International Symposium on Symmetries in Subatomic Physics, Seattle 199

    Maxwell-Drude-Bloch dissipative few-cycle optical solitons

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    We study the propagation of few-cycle pulses in two-component medium consisting of nonlinear amplifying and absorbing two-level centers embedded into a linear and conductive host material. First we present a linear theory of propagation of short pulses in a purely conductive material, and demonstrate the diffusive behavior for the evolution of the low-frequency components of the magnetic field in the case of relatively strong conductivity. Then, numerical simulations carried out in the frame of the full nonlinear theory involving the Maxwell-Drude-Bloch model reveal the stable creation and propagation of few-cycle dissipative solitons under excitation by incident femtosecond optical pulses of relatively high energies. The broadband losses that are introduced by the medium conductivity represent the main stabilization mechanism for the dissipative few-cycle solitons.Comment: 38 pages, 10 figures. submitted to Physical Review

    Complete Integrability of Geodesic Motion in General Kerr-NUT-AdS Spacetimes

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    We explicitly exhibit n-1 constants of motion for geodesics in the general D-dimensional Kerr-NUT-AdS rotating black hole spacetime, arising from contractions of even powers of the 2-form obtained by contracting the geodesic velocity with the dual of the contraction of the velocity with the (D-2)-dimensional Killing-Yano tensor. These constants of motion are functionally independent of each other and of the D-n+1 constants of motion that arise from the metric and the D-n = [(D+1)/2] Killing vectors, making a total of D independent constants of motion in all dimensions D. The Poisson brackets of all pairs of these D constants are zero, so geodesic motion in these spacetimes is completely integrable.Comment: 4 pages. We have now found that the geodesic motion is not just integrable, but completely integrabl

    Mobility gap in intermediate valent TmSe

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    The infrared optical conductivity of intermediate valence compound TmSe reveals clear signatures for hybridization of light dd- and heavy f-electronic states with m* ~ 1.6 m_0 and m* ~ 16 m_0, respectively. At moderate and high temperatures, the metal-like character of the heavy carriers dominate the low-frequency response while at low temperatures (T_N < T < 100 K) a gap-like feature is observed in the conductivity spectra below 10 meV which is assigned to be a mobility gap due to localization of electrons on local Kondo singlets, rather than a hybridization gap in the density of states

    Constants of Geodesic Motion in Higher-Dimensional Black-Hole Spacetimes

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    In [arXiv:hep-th/0611083] we announced the complete integrability of geodesic motion in the general higher-dimensional rotating black-hole spacetimes. In the present paper we prove all the necessary steps leading to this conclusion. In particular, we demonstrate the independence of the constants of motion and the fact that they Poisson commute. The relation to a different set of constants of motion constructed in [arXiv:hep-th/0612029] is also briefly discussed.Comment: 8 pages, no figure
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