Bias Voltage and Temperature Dependence of Hot Electron Magnetotransport

We present a qualitative model study of energy and temperature dependence of hot electron magnetotransport. This model calculations are based on a simple argument that the inelastic scattering strength of hot electrons is strongly spin and energy dependent in the ferromagnets. Since there is no clear experimental data to compare with this model calculations, we are not able to extract clear physics from this model calculations. However, interestingly this calculations display that the magnetocurrent increases with bias voltage showing high magnetocurrent if spin dependent imaginary part of proper self energy effect has a substantial contribution to the hot electron magnetotransport. Along with that, the hot electron magnetotransport is strongly influence by the hot electron spin polarization at finite temperatures

Large Cosmic Variance in the Clustering Properties of Lyman Alpha Emitters at z~5

We reported in a previous paper the discovery of large-scale structure of Lyman Alpha emitters (LAEs) at z=4.86+-0.03 with a projected size of 20 Mpc x 50 Mpc in narrow-band data of a 25' x 45' area of the Subaru Deep Field (Omega_0=0.3, lambda_0=0.7, H0=70 km/s/Mpc). However, the surveyed area, which corresponds to 55 Mpc x 100 Mpc, was not large enough that we can conclude that we are seeing a typical distribution of z~5 LAEs. In this Letter, we report the results of follow-up imaging of the same sky area using a new narrow-band filter (NB704, lambda_c=7046 A and FWHM=100 A) to detect LAEs at z=4.79, i.e., LAEs lying closer to us by 39 Mpc on average than the z=4.86 objects. We detect 51 LAEs at z=4.79+-0.04 down to NB704=25.7, and find that their sky distribution is quite different from the z=4.86 LAEs'. The clustering of z=4.79 LAEs is very weak on any scales and there is no large-scale high- contrast structure. The shape and the amplitude of the angular correlation function are thus largely different between the two samples. These results demonstrate a large cosmic variance in the clustering properties of LAEs on scales of ~ 50 Mpc.Comment: 4 pages (uses emulateapj5.sty), accepted for ApJ

Analytic smoothing effect for solutions to Schrödinger equations with nonlinearity of integral type

We study analytic smoothing effects for solutions to the Cauchy problem for the Schr\"odinger equation with interaction described by the integral of the intensity with respect to one direction in two space dimensions. The only assumption on the Cauchy data is the weight condition of exponential type and no regularity assumption is imposed

Direct Observation of Nonequivalent Fermi-Arc States of Opposite Surfaces in Noncentrosymmetric Weyl Semimetal NbP

We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) on noncentrosymmetric Weyl semimetal candidate NbP, and determined the electronic states of both Nb- and P-terminated surfaces corresponding to the "opposite" surfaces of a polar crystal. We revealed a drastic difference in the Fermi-surface topology between the opposite surfaces, whereas the Fermi arcs on both surfaces are likely terminated at the surface projection of the same bulk Weyl nodes. Comparison of the ARPES data with our first-principles band calculations suggests notable difference in electronic structure at the Nb-terminated surface between theory and experiment. The present result opens a platform for realizing exotic quantum phenomena arising from unusual surface properties of Weyl semimetals.Comment: 5 pages, 4 figure

AA-cation control of magnetoelectric quadrupole order in AA(TiO)Cu4_4(PO4_4)4_4 (AA = Ba, Sr, and Pb)

Ferroic magnetic quadrupole order exhibiting macroscopic magnetoelectric activity is discovered in the novel compound $A$(TiO)Cu$_4$(PO$_4$)$_4$ with $A$ = Pb, which is in contrast with antiferroic quadrupole order observed in the isostructural compounds with $A$ = Ba and Sr. Unlike the famous lone-pair stereochemical activity which often triggers ferroelectricity as in PbTiO$_3$, the Pb$^{2+}$ cation in Pb(TiO)Cu$_4$(PO$_4$)$_4$ is stereochemically inactive but dramatically alters specific magnetic interactions and consequently switches the quadrupole order from antiferroic to ferroic. Our first-principles calculations uncover a positive correlation between the degree of $A$-O bond covalency and a stability of the ferroic quadrupole order.Comment: 7 pages, 4 figure