Kouji Segawa

Electrical resistivity anisotropy from self-organized one dimensionality in high-temperature superconductors

We investigate the manifestation of stripes in the in-plane resistivity anisotropy in untwinned single crystals of La2-xSrxCuO4 ( x = 0.02-0.04) and YBa(2)Cu(3)O(y) ( y = 6.35-7.0). It is found that both systems show strongly temperature-dependent in-plane anisotropy in the lightly hole-doped region and that the anisotropy in YBa(2)Cu(3)O(y) grows with decreasing y below approximately 6.60 despite the decreasing orthorhombicity, which gives most direct evidence that electrons self-organize into a macroscopically anisotropic state. The transport is found to be easier along the direction of the spin stripes already reported, demonstrating that the stripes are intrinsically conducting in cuprates.

Mobility of the doped holes and the antiferromagnetic correlations in underdoped high- Tc cuprates.

The emergence and the evolution of the metallic charge transport in the La2-xSrxCuO4 system from lightly to optimally doped samples (x = 0.01-0.17) are studied. We demonstrate that in high-quality single crystals the in-plane resistivity shows a metallic behavior for all values of x at moderate temperatures and that the hole mobility at 300 K changes only by a factor of 3 from x = 0.01 to 0.17, where its x dependence is found to be intriguingly similar to that of the inverse antiferromagnetic correlation length. We discuss an incoherent-metal picture and a charged-stripe scenario as candidates to account for these peculiar features.

SPECIFIC-HEAT EVIDENCE FOR STRONG ELECTRON CORRELATIONS IN THE THERMOELECTRIC MATERIAL (NA, CA)CO2O4

The specific heat of

Evolution of the Hall Coefficient and the Peculiar Electronic Structure of the Cuprate Superconductors

(mathrm{N}mathrm{a},mathrm{C}mathrm{a}){mathrm{Co}}_{2}{mathrm{O}}_{4}

Spin-rotation symmetry breaking in the superconducting state of CuxBi2Se3

is measured at low-temperatures to determine the magnitude of the electronic specific-heat coefficient

Magnetoresistance of Untwinned YBa 2 Cu 3 O y Single Crystals in a Wide Range of Doping: Anomalous Hole-Doping Dependence of the Coherence Length

ensuremath{gamma},

Intrinsic Hall response of theCuO2planes in a chain-plane composite system ofYBa2Cu3Oy

in an attempt to gain an insight into the origin of the unusually large thermoelectric power of this compound. It is found that

Direct observation of nonequivalent Fermi-arc states of opposite surfaces in the noncentrosymmetric Weyl semimetal NbP

ensuremath{gamma}

Coherence and Superconductivity in Coupled One-Dimensional Chains: A Case Study of YBa2Cu3Oy

is as large as

Hall effect in Zn-doped YBa 2 Cu 3 O 7 − δ revisited: Hall angle and the pseudogap

ensuremath{sim}48 {mathrm{m}mathrm{J}/mathrm{m}mathrm{o}mathrm{l}mathrm{K}}^{2},