Okawa, M., Ishizaka, K., Uchiyama, H., Tadatomo, H., Masui, T., Tajima, S., ...
Low energy structure of optimally doped YBa2Cu3O7-delta is investigated using laser-excited angle-resolved photoemission spectroscopy. The surface state and the CuO chain band that usually overlap...
Search for Sub-threshold Photoproduction of J/Psi Mesons (2008)
Bosted, P., Dunne, J., Lee, C. A., Junnarkar, P., Arrington, J., Asaturyan, R., ...
A search was made for sub-threshold $J/\psi$ production from a carbon target using a mixed real and quasi-real Bremsstrahlung photon beam with an endpoint energy of 5.76 GeV. No events were observed,...
Beyer, A. D., Grinolds, M. S., Teague, M. L., Tajima, S.
We report spatially resolved scanning tunneling spectroscopic studies of a high-$T_c$ superconductor $YBa_2Cu_3O_{7-\delta}$ as a function of magnetic field. Our data reveal intra-vortex pseudogap...
An Isotopic Fingerprint of Electron-Phonon Coupling in High-Tc Cuprates (2008)
Iwasawa, H., Douglas, J. F., Sato, K., Masui, T., Yoshida, Y., Sun, Z., ...
Angle-resolved photoemission spectroscopy with low-energy tunable photons along the nodal direction of oxygen isotope substituted Bi2Sr2CaCu2O8+delta reveals a distinct oxygen isotope shift near the...
Mukuda, H., Terasaki, N., Kinouchi, H., Yashima, M., Kitaoka, Y., Suzuki, S., ...
We report 75As-NQR/NMR studies on the oxygen-deficient iron(Fe)-based oxypnictide superconductors LaFeAsO_{0.6} (T_c=28 K) along with the results on LaFeAsO, LaFeAsO_{0.75}(T_c=20 K) and...
Carlo, J. P., Uemura, Y. J., Goko, T., MacDougall, G. J., Rodriguez, J. A., Yu, W., ...
Muon spin relaxation (MuSR) measurements in iron oxy-pnictide systems have revealed: (1) commensurate long-range order in undoped LaOFeAs; (2) Bessel function line shape in La(O0.97F0.03)FeAs which...
Rapid change of electronic anisotropy in overdoped (Y,Ca)Ba2Cu3O7-d (2008)
Nagasao, K., Masui, T., Tajima, S.
Electronic anisotropy was studied for overdoped (Y,Ca)Ba2Cu3O7-d with various doping levels (p). It was found that the pseudogap-like behavior in the resistivity disappear when p exceeds 0.17,...
Superconducting gap of overdoped Tl2Ba2CuO6+d observed by Raman scattering (2007)
Nishikawa, K., Masui, T., Tajima, S., Eisaki, H., Kito, H., Iyo, A.
We report Raman scattering spectra for single crystals of overdoped Tl2Ba2CuO6+d (Tl-2201) at low temperatures. It was observed that the pair-breaking peaks in A1g and B1g spectra radically shift to...
Ishii, K., Hoesch, M., Inami, T., Kuzushita, K., Ohwada, K., Tsubota, M., ...
We report a Cu K-edge resonant inelastic x-ray scattering (RIXS) study of high-Tc cuprates. Momentum-resolved charge excitations in the CuO2 plane are examined from parent Mott insulators to...
Universal observation of multiple order parameters in cuprate superconductors (2007)
Khasanov, R., Strässle, S., Di Castro, D., Masui, T., Miyasaka, S., Tajima, S., ...
The temperature dependence of the London penetration depth \lambda was measured for an untwined single crystal of YBa_2Cu_3O_{7-\delta} along the three principal crystallographic directions (a, b,...
Quasifree Lambda, Sigma^0, and Sigma^- electroproduction from 1,2H, 3,4He, and carbon (2007)
Dohrmann, F., Ahmidouch, A., Armstrong, C. S., Arrington, J., Asaturyan, R., Avery, S., ...
Kaon electroproduction from light nuclei and hydrogen, using 1H, 2H, 3He, 4He, and Carbon targets has been measured at Jefferson Laboratory. The quasifree angular distributions of Lambda and Sigma...
Compton Scattering Cross Section on the Proton at High Momentum Transfer (2007)
Danagoulian, A., H. Mamyan, V., Roedelbronn, M., A. Aniol, K., Bertin, P.Y., ...
Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s = 5-11 and -t = 2-7 GeV2 with statistical accuracy of a few percent. The scaling...
Polarization Transfer in Proton Compton Scattering at High Momentum Transfer (2007)
J. Hamilton, D., H. Mamyan, V., A. Aniol, K., Y. Bertin, P., Bimbot, L., ...
Compton scattering from the proton was investigated at s =(6.9 GeV)**2 and t = (-4.0 GeV)**2 via polarization transfer from circularly polarized incident photons. The longitudinal and transverse...
Electrodynamics of the vortex lattice in untwinned YBaCuO by complex impedance measurements (2007)
Pautrat, A., Daignere, A., Goupil, C., Simon, Ch., Andrzejewski, B., Rykov, A. I., ...
We report complex impedance measurements in an untwinned YBaCuO crystal. Our broad frequency range covers both the quasi static response and the resistive response of the vortex lattice. It allow us...
Two-phonon contributions to inelastic x-ray scattering spectra of MgB2 (2007)
Baron, A. Q. R., Uchiyama, H., Heid, R., Tanaka, Y., Tsutsui, S., ...
Two-phonon contributions to meV-resolved inelastic x-ray scattering spectra of MgB2 at 300K are identified, in good agreement, in both intensity and energy, with a harmonic calculation using the...
Oxygen Phonon Branches in Detwinned YBa2Cu3O7 (2007)
Reznik, D., Pintschovius, L., Reichardt, W., Endoh, Y., Hiraka, H., Tranquada, J. M., ...
We report results of inelastic neutron scattering measurements of phonon dispersions on a detwinned sample of YBaCu3O7 and compare them with model calculations. Plane oxygen bond stretching phonon...
Local moment fluctuations in an optimally-doped high Tc superconductor (2006)
Reznik, D., Eremin, I., Pintschovius, L., Arai, M., Endoh, Y., ...
We present results of neutron scattering experiments on YBa2Cu3O6.95 (Tc=93K). Our results indicate that magnetic collective modes due to correlated local moments are present both above and below Tc...
Spin Gap in Optimally-doped YBCO (2006)
Reznik, D., Pintschovius, L., Endoh, Y., Bourges, P., Sidis, Y., Masui, T., ...
Spin gap in optimally-doped YBCO was investigated by inelastic neutron scattering. We found that q-integrated spectral weight in the vicinity of the spin gap has a shape of a step function at 10K...
Proton Spin Structure in the Resonance Region (2006)
Slifer, K., Tajima, S., Aghalaryan, A., Ahmidouch, A., Asaturyan, R., ...
We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q^2 = 1.3 GeV^2. Using the Jefferson Lab...
On the Origin of the Double Superconducting Transition in Overdoped YBa2Cu3Ox (2005)
Lortz, R., Tomita, T., Wang, Y., Junod, A., Schilling, J. S., Masui, T., ...
The superconducting transition in a single overdoped, detwinned YBa2Cu3Ox (YBCO) crystal is studied using four different probes. Whereas the AC and DC magnetic susceptibilities find a dominant...
Tsuda, S, Yokoya, T, Kiss, T, Shimojima, T, Shin, S, Togashi, T, ...
"Sub-meV" resolution photoemission spectroscopy was used to study carbon-substitution dependence of the multiple superconducting gap of Mg(B1-xCx)(2). Two features corresponding to sigma and pi gaps...
Polarization Transfer in Proton Compton Scattering at High Momentum Transfer (2005)
J. Hamilton, D., H. Mamyan, V., A. Aniol, K., Y. Bertin, P., Bimbot, L., ...
Compton scattering from the proton was investigated at s =(6.9 GeV)**2 and t = (-4.0 GeV)**2 via polarization transfer from circularly polarized incident photons. The longitudinal and transverse...
Polarization Transfer in Proton Compton Scattering at High Momentum Transfer (2005)
J. Hamilton, D., H. Mamyan, V., A. Aniol, K., Y. Bertin, P., Bimbot, L., ...
Compton scattering from the proton was investigated at s =(6.9 GeV)**2 and t = (-4.0 GeV)**2 via polarization transfer from circularly polarized incident photons. The longitudinal and transverse...
Effects of carbon incorporation on doping state of YBa2Cu3Oy (2004)
Yamamoto, A., Hirose, K., Itoh, Y., Kakeshita, T., Tajima, S.
Effects of carbon incorporation on the doping state of YBa2Cu3Oy (Y-123) were investigated. Quantitative carbon analysis revealed that carbon could be introduced into Y-123 from both the precursor...
Pressure dependence of the upper critical field of MgB2 and of YNi2B2C (2004)
Suderow, H., Tissen, V. G., Brison, J. P., Martinez, J. L., Vieira, S., Lejay, P., ...
We present measurements of H$_{c2}(T)$ under pressure in MgB$_2$ and in YNi$_2$B$_2$C. The changes in the shape of H$_{c2}(T)$ are interpreted within current models and show the evolution of the main...
Savici, A. T., Fukaya, A., Gat-Malureanu, I. M., Ito, T., Russo, P. L., Uemura, Y. J., ...
Muon spin relaxation ($\mu$SR) measurements in high transverse magnetic fields ($\parallel \hat c$) revealed strong field-induced quasi-static magnetism in the underdoped and Eu doped...
Vasquez, R., Yen, N-C., Fu, C-C., Chen, C-T., Huang, Z., Tajima, S.
The pairing symmetry and the superconducting gap in high-temperature superconducting cuprates are investigated as a function of the hole doping level (x) and temperature (T), using directional...
Yeh, N. C., Chen, C. T., Vasquez, R. P., Jung, C. U., Kim, J. Y., Park, M. S., ...
We report scanning tunneling spectroscopic studies of the effects of quantum impurities in cuprate superconductors.
Mott gap excitations in twin-free YBa2Cu3O7-d (Tc = 93 K) studied by RIXS (2004)
Ishii, K., Tsutsui, K., Endoh, Y., Tohyama, T., Kuzushita, K., Inami, T., ...
Mott gap excitations in the high-Tc superconductor of the optimal doped YBa2Cu3O7-d (Tc = 93 K) have been studied by the resonant inelastic x-ray scattering method. Anisotropic spectra in the...
Tsuda, S., Yokoya, T., Kiss, T., Shimojima, T., Shin, S., Togashi, T., ...
``Sub-meV'' resolution photoemission spectroscopy was used to study carbon-substitution dependence on the multiple superconducting gap of Mg(B$_{1 - x}$C$_{x})_{2}$. Two features corresponding to...
Softening of Cu-O bond stretching phonon in tetragonal HgBa$_2$CuO$_{4+\delta}$ (2004)
Uchiyama, H., Baron, A. Q. R., Tsutsui, S., Tanaka, Y., Yamamoto, A., ...
Phonons in nearly optimally doped HgBa$_2$CuO$_{4+\delta}$ were studied by inelastic X-ray scattering. The dispersion of the low energy modes is well described by a shell model, while the Cu-O bond...
Excess current in point contacts on two-band superconductor MgB$_2$ in magnetic field (2004)
Naidyuk, Yu. G., Kvitnitskaya, O. E., Yanson, I. K., Lee, S., Tajima, S.
Series of $I(V)$ characteristic and bias-dependent differential resistance $dV/dI(V)$ for point-contacts on the single crystals of two-band superconductor MgB$_2$ were measured in magnetic field up...
Tajima, S., Fudamoto, Y., Kakeshita, T., Gorshunov, B., Železný, V., Kojima, K. M., ...
Temperature dependences of the optical spectra of La$_{2-x}$Sr$_x$CuO$_4$ with $x$=0.12 and 0.15 were carefully examined for a polarization parallel to the CuO$_2$-plane over a wide frequency range...
Spin Dynamics in High-Tc Superconductor YBa2Cu3O6.9 (2004)
Yokoo, T, Arai, M, Frost, C D, Endoh, Y, Egami, T, Shiohara, Y, ...
Spin Dynamics in High-Tc Superconductor Yba2Cu3O6.9 (2004)
Yokoo, T, Arai, M, Frost, C D, Endoh, Y, Egami, T, Shiohara, Y, ...
Carbon-substitution effect on the electronic properties of MgB$_2$ single crystals (2003)
Masui, T., Lee, S., Tajima, S.
The electronic properties of the carbon substituted MgB$_2$ single crystals are reported. The carbon substitution drops T$_c$ below 2 K. In-plane resistivity shows a remarkable increase in residual...
Influence of carbon doping in the vortex matter properties of MgB$_2$ (2003)
Pissas, M., Stamopoulos, D., Lee, S., Tajima, S.
We have studied the vortex-matter phase diagram of low C doped MgB$_2$ superconductor. The significant finding is the appearance of a peak effect, which, as both our global magnetization and local ac...
Enhancement of the irreversibility field by carbon substitution in single crystal MgB$_2$ (2003)
Ohmichi, E., Masui, T., Lee, S., Tajima, S., Osada, T.
We report the detailed study of the irreversibility field {\hirr} of single crystals of Mg(B$_{1-x}$C$_{x}$)$_2$ ($x$=0, 2, 3.5, 5 and 7%) in strong magnetic fields of up to 40 T. High sensitive...
The vortex depinning transition in untwinned YBaCuO using complex impedance measurements (2003)
Pautrat, Alain, Goupil, Christophe, Simon, Charles, Andrewjewski, Bart, Rykov, A.I., Tajima, S.
We present surface impedance measurement of the vortex linear response in alarge untwinned YBCO crystal. The depinning spectra obtained over a broadfrequency range (100 Hz- 30 MHz) are those of a...
The vortex depinning transition in untwinned YBaCuO using complex impedance measurements (2003)
Pautrat, Alain, Goupil, Christophe, Simon, Charles, Andrewjewski, Bart, Rykov, A.I., Tajima, S.
We present surface impedance measurement of the vortex linear response in alarge untwinned YBCO crystal. The depinning spectra obtained over a broadfrequency range (100 Hz- 30 MHz) are those of a...
The vortex depinning transition in untwinned YBaCuO using complex impedance measurements (2003)
Pautrat, Alain, Goupil, Christophe, Simon, Charles, Andrewjewski, Bart, Rykov, A.I., Tajima, S.
We present surface impedance measurement of the vortex linear response in alarge untwinned YBCO crystal. The depinning spectra obtained over a broadfrequency range (100 Hz- 30 MHz) are those of a...
The vortex depinning transition in untwinned YBaCuO using complex impedance measurements (2003)
Pautrat, Alain, Goupil, Christophe, Simon, Charles, Andrewjewski, Bart, Rykov, A. I., Tajima, S.
We present surface impedance measurement of the vortex linear response in a large untwinned YBCO crystal. The depinning spectra obtained over a broad frequency range (100 Hz- 30 MHz) are those of a...
The vortex depinning transition in untwinned YBaCuO using complex impedance measurements (2003)
Pautrat, Alain, Goupil, Christophe, Simon, Charles, Andrewjewski, Bart, Rykov, A.I., Tajima, S.
We present surface impedance measurement of the vortex linear response in alarge untwinned YBCO crystal. The depinning spectra obtained over a broadfrequency range (100 Hz- 30 MHz) are those of a...
Oxygen Phonon Branches in YBa2Cu3O7 (2003)
Pintschovius, L., Reznik, D., Reichardt, W., Endoh, Y., Hiraka, H., Tranquada, J. M., ...
We report results of inelastic neutron scattering measurements of phonon dispersions in optimally doped YBa2Cu3O6.95 and compare them with model calculations. The focus is on the in-plane oxygen...
Kohn Anomaly in MgB2 by Inelastic X-Ray Scattering (2003)
Baron, A. Q. R., Uchiyama, H., Tanaka, Y., Tsutsui, S., Ishikawa, D., Lee, S., ...
We study phonons in MgB2 using inelastic x-ray scattering (1.6 and 6 meV resolution). Our measurements show excellent agreement with theory for the dispersion and line-width: we clearly observe the...
Evidence for Dynamic Charge Stripes in the Phonons of Optimally Doped YBCO (2003)
Pintschovius, L., Endoh, Y., Reznik, D., Hiraka, H., Tranquada, J. M., Reichardt, W., ...
Inelastic neutron scattering investigations on optimally doped YBCO revealed a very pronounced temperature dependence in the Cu-O in-plane bond-stretching vibrations along the (010) direction: a...
Raman study of carrier-overdoping effects on the gap in high-Tc superconducting cuprates (2003)
Masui, T., Limonov, M., Uchiyama, H., Lee, S., Tajima, S., Yamanaka, A.
Raman scattering in the heavily overdoped (Y,Ca)Ba_2Cu_3O_{7-d} (T_c = 65 K) and Bi_2Sr_2CaCu_2O_{8+d} (T_c = 55 K) crystals has been investigated. For the both crystals, the electronic pair-breaking...
Dispersion of Magnetic Excitations in Superconducting Optimally Doped YBa_2Cu_3O_6.95 (2003)
Reznik, D., Bourges, P., Pintschovius, L., Endoh, Y., Sidis, Y., Matsui, T., ...
Detailed neutron scattering measurements of YBa_2Cu_3O_6.95 found that the resonance peak and incommensurate magnetic scattering induced by superconductivity represent the same physical phenomenon:...
Nakamura, J., Nasubida, S., Kabasawa, E., Yamazaki, H., Yamada, N., Kuroki, K., ...
The effect of electron correlation (EC) on the electronic structure in MgB$_2$, AlB$_2$ and ZrB$_2$, is studied by examining the partial density of states (PDOS) of B-2$p\sigma$ and $p\pi$ orbitals...
Two Pseudogaps in the Cuprates: Meingast et al. Reply (2003)
Meingast, C., Pasler, V., Nagel, P., Rykov, A., Tajima, S., Olsson, P.
In classical superconductors Cooper-pair formation and phase coherence occur simultaneously as the temperature is lowered below Tc. In high-temperature superconductors (HTSC), on the other hand, the...
Lortz, R., Meingast, C., Rykov, A. I., Tajima, S.
The effect of strong magnetic fields (11 T) on superconductivity in YBa2Cu3O7-d is investigated using high-resolution thermal expansion. We show that the field-induced broadening of the...
Anomalous Flux Flow Resistivity in Two Gap Superconductor MgB_2 (2003)
Shibata, A., Matsumoto, M., Izawa, K., Matsuda, Y., Lee, S., Tajima, S.
The flux flow resistivity associated with purely viscous motion of vortices in high-quality MgB_2 was measured by microwave surface impedance. Flux flow resistivity exhibits unusual field dependence...
Aegerter, C. M., Keller, H., Lloyd, S. H., Kealey, P. G., Forgan, E. M., Johnson, S. T., ...
We present a study of the vortex lattice in untwinned YBa$_2$Cu$_3$O$_{7-x}$ crystals, using a combination of muon spin rotation and neutron small angle scattering measurements. Both methods show a...
Scanning tunneling spectroscopic studies of the pairing state of cuprate superconductors (2003)
Vasquez, R. P., Jung, C. U., Yoshida, K., ...
Quasiparticle tunneling spectra of both hole-doped (p-type) and electron-doped (n-type) cuprates are studied using a low-temperature scanning tunneling microscope. The results reveal that neither the...
Electrodynamics of the vortex lattice in untwinned YBaCuO by complex impedance measurements (2003)
Pautrat, A., Daignere, A., Goupil, C., Simon, Ch., Andrzejewski, B., Rykov, A. I., ...
We report complex impedance measurements in an untwinned YBaCuO crystal. Our broad frequency range covers both the quasi static response and the resistive response of the vortex lattice. It allow us...
Determination of the Fermi Surface of MgB$_2$ by the de Haas-van Alphen effect (2003)
Carrington, A., Meeson, P. J., Cooper, J. R., Balicas, L., Hussey, N. E., Yelland, E. A., ...
We report measurements of the de Haas-van Alphen effect for single crystals of MgB$_2$, in magnetic fields up to 32 Tesla. In contrast to our earlier work, dHvA orbits from all four sheets of the...
Tajima, S., Uchida, S., Basov, D. N.
Recently Lucarelli {\it et al.} have reported\cite{lucarelli} temperature-dependence of the in-plane optical reflectivity of La$_{2-x}$Sr$_x$CuO$_4$ over a wide doping range, focusing on the infrared...