T. Uefuji

Commensurate spin dynamics in the superconducting state of an electron-doped cuprate superconductor

We report neutron scattering studies on two single crystal samples of the electron-doped (n-type) superconducting (SC) cuprate Nd2-xCexCuO4 (x=0.15) with T(c)=18 and 25 K. Unlike the hole-doped (p-type) SC cuprates, where incommensurate magnetic fluctuations commonly exist, the n-type cuprate shows commensurate magnetic fluctuations at the tetragonal (1/2 1/2 0) reciprocal points both in the SC and in the normal state. A spin gap opens up when the n-type cuprate becomes SC, as in the optimally doped p-type La2-xSrxCuO4. The gap energy, however, increases gradually up to about 4 meV as T decreases from T(c) to 2 K, which contrasts with the spin pseudogap behavior with a T-independent gap energy in the SC state of p-type cuprates.

Angle-resolved photoemission spectroscopy of the antiferromagnetic superconductor Nd1.87Ce0.13CuO4: Anisotropic spin-correlation gap, pseudogap, and the induced quasiparticle mass enhancement

We performed high-resolution angle-resolved photoemission spectroscopy on Nd1.87Ce0.13CuO4, which is located at the boundary of the antiferromagnetic (AF) and the superconducting phase. We observed that the quasiparticle (QP) effective mass around (pi,0) is strongly enhanced due to the opening of the AF gap. The QP mass and the AF gap are found to be anisotropic, with the largest value near the intersecting point of the Fermi surface and the AF zone boundary. In addition, we observed that the QP peak disappears around the Néel temperature (TN) while the AF pseudogap is gradually filled up at much higher temperatures, possibly due to the short-range AF correlation.

Magnetic and superconducting phase diagram of electron-doped Pr1-xLaCexCuO4

We have investigated the magnetism and the superconductivity of the electron-doped

Electron-doping effect on magnetic order and superconductivity in Nd2−xCexCuO4 single crystals

{\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{LaCe}}_{x}{\mathrm{CuO}}_{4}

Absence of a magnetic-field effect on static magnetic order in the electron-doped superconductor Nd 1.86 Ce 0.14 CuO 4

by means of zero-field muon spin rotation/relaxation and magnetic susceptibility measurements. At low temperatures, a well-defined muon spin rotation free from the effect of rare-earth moments was observed for samples with

Phase diagram of the electron-doped superconductor Pr1−xLaCexCuO4−δ

xl~0.08

Superconducting phase diagram of electron-doped cuprates Nd2−xCexCuO4

corresponding to the antiferromagnetic (AF) order of Cu spins. Bulk superconductivity was identified in a wide Ce concentration range of

A comparative study on the magnetic order in hole- and electron-doped high-Tc cuprates

0.09l~xl~0.20

Superconducting phase diagram of La2−xSrxCuO4 studied using single crystals with Sr-concentration gradient

with a maximum transition temperature of 26 K. Abrupt appearance of the superconducting (SC) phase at

Structural effect on the stability of magnetic order in La1.875Ba0.125−xSrxCuO4

x\ensuremath{\sim}0.09