Ayako Yamamoto

2018

Charge dynamics and metal-insulator transition in perovskite SrIr_1−xSn_xO₃

Fujioka, J., Okawa, T., Masuko, M., Yamamoto, A. & Tokura, Y., 2018 1 1, ： : Journal of the Physical Society of Japan. 87, 12, 123706.

研究成果: Article

insulators

orbitals

metals

metalloids

substitutes

2017

17 引用 (Scopus)

Correlated Dirac semimetallic state with unusual positive magnetoresistance in strain-free perovskite SrIrO3

Fujioka, J., Okawa, T., Yamamoto, A. & Tokura, Y., 2017 3 3, ： : Physical Review B. 95, 12, 121102.

研究成果: Article

magnetoresistivity

Magnetoresistance

Perovskite

Paramagnetism

Galvanomagnetic effects

3 引用 (Scopus)

Evidence for Weakly Correlated Oxygen Holes in the Highest- Tc Cuprate Superconductor HgBa2Ca2Cu3 O8+δ

Chainani, A., Sicot, M., Fagot-Revurat, Y., Vasseur, G., Granet, J., Kierren, B., Moreau, L., Oura, M., Yamamoto, A., Tokura, Y. & Malterre, D., 2017 7 31, ： : Physical Review Letters. 119, 5, 057001.

研究成果: Article

cuprates

photoelectric emission

x ray absorption

x ray spectroscopy

absorption spectroscopy

1 引用 (Scopus)

Magnetic susceptibility of optimally doped HgBa2CuO4+δ

Itoh, Y., Machi, T. & Yamamoto, A., 2017 12 13, ： : Physical Review B. 96, 23, 235118.

研究成果: Article

Magnetic susceptibility

Powders

Superconducting materials

Charge transfer

rocks

4 引用 (Scopus)

S= 12 quantum critical spin ladders produced by orbital ordering in Ba2CuTeO6

Gibbs, A. S., Yamamoto, A., Yaresko, A. N., Knight, K. S., Yasuoka, H., Majumder, M., Baenitz, M., Saines, P. J., Hester, J. R., Hashizume, D., Kondo, A., Kindo, K. & Takagi, H., 2017 3 21, ： : Physical Review B. 95, 10, 104428.

研究成果: Article

Ladders

ladders

orbitals

Exchange coupling

Neutron diffraction

6 引用 (Scopus)

Ultraslow fluctuations in the pseudogap states of HgBa2CaCu2 O6+δ

Itoh, Y., Machi, T. & Yamamoto, A., 2017 3 6, ： : Physical Review B - Condensed Matter and Materials Physics. 95, 9, 094501.

研究成果: Article

Exponential functions

exponential functions

nuclear spin

cuprates

echoes

2015

2 引用 (Scopus)

Coexistence of monochalocogen and dichalocogen ions in BiSe₂ and BiS₂ crystals prepared at high pressure

Yamamoto, A., Hashizume, D., Bahramy, M. S. & Tokura, Y., 2015 4 20, ： : Inorganic Chemistry. 54, 8, p. 4114-4119 6 p.

研究成果: Article

Ions

Crystals

crystals

ions

Substitution reactions

16 引用 (Scopus)

High pressure effects revisited for the cuprate superconductor family with highest critical temperature

Yamamoto, A., Takeshita, N., Terakura, C. & Tokura, Y., 2015 12 1, ： : Nature Communications. 6, 8990.

研究成果: Article

High pressure effects

pressure effects

cuprates

critical temperature

electrical resistivity

9 引用 (Scopus)

Thermal conductivity across the metal-insulator transition in the single-crystalline hyperkagome antiferromagnet Na3+xIr3 O8

Fauqué, B., Xu, X., Bangura, A. F., Hunter, E. C., Yamamoto, A., Behnia, K., Carrington, A., Takagi, H., Hussey, N. E. & Perry, R. S., 2015 2 25, ： : Physical Review B - Condensed Matter and Materials Physics. 91, 7, 075129.

研究成果: Article

Metal insulator transition

Thermal conductivity

thermal conductivity

insulators

Scattering

2013

2 引用 (Scopus)

Quantifying covalency and metallicity in correlated compounds undergoing metal-insulator transitions

Chainani, A., Yamamoto, A., Matsunami, M., Eguchi, R., Taguchi, M., Takata, Y., Takagi, H., Shin, S., Nishino, Y., Yabashi, M., Tamasaku, K. & Ishikawa, T., 2013 1 9, ： : Physical Review B - Condensed Matter and Materials Physics. 87, 4, 045108.

研究成果: Article

Metal insulator transition

metal compounds

metallicity

insulators

Screening

36 引用 (Scopus)

Zero resistivity above 150K in HgBa₂Ca₂Cu ₃O_8+δ at high pressure

Takeshita, N., Yamamoto, A., Iyo, A. & Eisaki, H., 2013 2, ： : Journal of the Physical Society of Japan. 82, 2, 023711.

研究成果: Article

electrical resistivity

hydrostatic pressure

superconductivity

transition temperature

signatures

2012

55 引用 (Scopus)

Strong coupling superconductivity at 8.4 K in an antiperovskite phosphide SrPt ₃P

Takayama, T., Kuwano, K., Hirai, D., Katsura, Y., Yamamoto, A. & Takagi, H., 2012 6 8, ： : Physical Review Letters. 108, 23, 237001.

研究成果: Article

phosphides

phonons

superconductivity

heavy fermion superconductors

Fermi surfaces

2011

Metal-Insulator Transition and Magnetic Order in the Pyrochlore Oxide Hg2Ru2O7

Yamamoto, A., Yoshida, M. & Takigawa, M., 2011, ： : Journal of the Physical Society of Japan.

研究成果: Article

5 引用 (Scopus)

Superconducting Phase at 7.7 K in the Hg_xReO₃ Compound with a Hexagonal Bronze Structure

Ohgushi, K., Yamamoto, A., Kiuchi, Y., Ganguli, C., Matsubayashi, K., Uwatoko, Y. & Takagi, H., 2011 1 4, ： : Physical Review Letters. 106, 1, 017001.

研究成果: Article

bronzes

superconductivity

rhenium

phonons

transition temperature

2010

8 引用 (Scopus)

Magnetic ground state of pyrochlore oxides close to metal-insulator boundary probed by muon spin rotation

Miyazaki, M., Kadono, R., Satoh, K. H., Hiraishi, M., Takeshita, S., Koda, A., Yamamoto, A. & Takagi, H., 2010 9 8, ： : Physical Review B - Condensed Matter and Materials Physics. 82, 9, 094413.

研究成果: Article

Metal insulator boundaries

muon spin rotation

Metal insulator transition

Magnetism

Oxides

1 引用 (Scopus)

On the possibility of MgB₂-like superconductivity in potassium hexaboride

Katsura, Y., Yamamoto, A., Ogino, H., Horii, S., Shimoyama, J. I., Kishio, K. & Takagi, H., 2010 12, ： : Physica C: Superconductivity and its Applications. 470, SUPPL.1

研究成果: Article

Superconductivity

Potassium

potassium

superconductivity

Boron

18 引用 (Scopus)

Superconductivity in 4d and 5d transition metal layered pnictides BaRh ₂P₂, BaIr₂P₂ and SrIr ₂As₂

Hirai, D., Takayama, T., Hashizume, D., Higashinaka, R., Yamamoto, A., Hiroko, A. K. & Takagi, H., 2010 12, ： : Physica C: Superconductivity and its Applications. 470, SUPPL.1

研究成果: Article

Group 5A compounds

Superconductivity

Transition metals

superconductivity

transition metals

6 引用 (Scopus)

Ten layered hexagonal perovskite Sr₅Ru_5-xO ₁₅ (x = 0.90), a weak ferromagnet with a giant coercive field H _c ∼ 12 T

Yamamoto, A., Hashizume, D., Katori, H. A., Sasaki, T., Ohmichi, E., Nishizaki, T., Kobayashi, N. & Takagi, H., 2010 10 26, ： : Chemistry of Materials. 22, 20, p. 5712-5717 6 p.

研究成果: Article

Coercive force

Perovskite

Ferromagnetic materials

Ferromagnetism

Curie temperature

2007

43 引用 (Scopus)

Fermi level shift in la_1-xSr_xMO₃ (M=Mn, Fe, Co, and Ni) probed by Schottky-like heteroepitaxial junctions with SrTi _0.99Nb_0.01O₃

Sawa, A., Yamamoto, A., Yamada, H., Fujii, T., Kawasaki, M., Matsuno, J. & Tokura, Y., 2007 8 2, ： : Applied Physics Letters. 90, 25, 252102.

研究成果: Article

shift

n-type semiconductors

metal oxides

transition metals

electrical properties

32 引用 (Scopus)

Metal-insulator transition in a pyrochlore-type ruthenium oxide, Hg ₂Ru₂O₇

Yamamoto, A., Sharma, P. A., Okamoto, Y., Nakao, A., Aruga Katori, H., Niitaka, S., Hashizume, D. & Takagi, H., 2007 4, ： : Journal of the Physical Society of Japan. 76, 4, 043703.

研究成果: Article

ruthenium

insulators

oxides

metals

valence

9 引用 (Scopus)

Pressure-induced transition from a correlated insulator to a fermi liquid observed in geometrically frustrated Hg ₂Ru ₂O ₇ pyrochlore

Takeshita, N., Terakura, C., Tokura, Y., Yamamoto, A. & Takagi, H., 2007 6, ： : Journal of the Physical Society of Japan. 76, 6, 063707.

研究成果: Article

Fermi liquids

insulators

metals

elementary excitations

hydrostatic pressure

2006

Phonon softening in HgBa₂CuO_4+δ and MgB ₂

Uchiyama, H., Baron, A. Q. R., Tsutsui, S., Tanaka, Y., Ishikawa, D., Lee, S., Hu, W. Z., Yamamoto, A., Heid, R., Bohnen, K. P., Ishikawa, T., Tajima, S. & Endoh, Y., 2006 1, ： : Journal of Physics and Chemistry of Solids. 67, 1-3, p. 294-297 4 p.

研究成果: Article

softening

Superconducting materials

Inelastic scattering

Superconductivity

X ray scattering

2005

7 引用 (Scopus)

Effects of carbon incorporation on doping state of YBa₂Cu ₃O_y

Yamamoto, A., Hirose, K., Itoh, Y., Kakeshita, T. & Tajima, S., 2005 5 1, ： : Physica C: Superconductivity and its Applications. 421, 1-4, p. 1-9 9 p.

研究成果: Article

Carbon

Doping (additives)

Oxygen

carbon

oxygen

Erratum: Effects of carbon incorporation on doping state of YBa ₂Cu₃O_y (Physica C: Superconductivity and its Applications (2005) 421 (1-9) DOI: 10.1016/j.physc.2005.02.006)

Yamamoto, A., Hirose, K., Itoh, Y., Kakeshita, T. & Tajima, S., 2005 11 15, ： : Physica C: Superconductivity and its Applications. 432, 3-4, p. 315 1 p.

研究成果: Article

Superconductivity

Carbon

superconductivity

Doping (additives)

carbon

2004

24 引用 (Scopus)

Carbon-substitution effect on superconducting properties in MgB₂ single crystals

Masui, T., Lee, S., Yamamoto, A., Uchiyama, H. & Tajima, S., 2004 10, ： : Physica C: Superconductivity and its Applications. 412-414, SPEC. ISS., p. 303-306 4 p.

研究成果: Article

Substitution reactions

Carbon

Single crystals

substitutes

carbon

60 引用 (Scopus)

Crystal growth of C-doped MgB₂ superconductors: Accidental doping and inhomogeneity

Lee, S., Masui, T., Yamamoto, A., Uchiyama, H. & Tajima, S., 2004 10, ： : Physica C: Superconductivity and its Applications. 412-414, SPEC. ISS., p. 31-35 5 p.

研究成果: Article

Crystallization

Crystal growth

Superconducting materials

crystal growth

inhomogeneity

6 引用 (Scopus)

Metallization of La_1/3NbO₃ by lithium incorporation

Yamamoto, A., Uchiyama, H. & Tajima, S., 2004 9 1, ： : Materials Research Bulletin. 39, 11, p. 1691-1699 9 p.

研究成果: Article

Metallizing

Lithium

Transport properties

lithium

transport properties

Phonon softening in HgBa₂CuO_4+δ observed by inelastic X-ray scattering

Uchiyama, H., Baron, A. Q. R., Tsutsui, S., Tanaka, Y., Hu, W. Z., Yamamoto, A., Tajima, S. & Endoh, Y., 2004 12 1, ： : Physica Status Solidi C: Conferences. 1, 11, p. 3130-3133 4 p.

研究成果: Article

softening

cuprates

scattering

x rays

transition temperature

61 引用 (Scopus)

Softening of Cu-O bond stretching phonons in tetragonal HgBa ₂CuO_4+δ

Uchiyama, H., Baron, A. Q. R., Tsutsui, S., Tanaka, Y., Hu, W. Z., Yamamoto, A., Tajima, S. & Endoh, Y., 2004 5 14, ： : Physical Review Letters. 92, 19, p. 197005-197001 5 p.

研究成果: Article

softening

phonons

x ray scattering

analyzers

crystallinity

2003

6 引用 (Scopus)

A Raman scattering study of superconductivity in MgB₂

Quilty, J. W., Lee, S., Yamamoto, A., Tajima, S. & Yamanaka, A., 2003 5, ： : Physica C: Superconductivity and its Applications. 388-389, p. 131-132 2 p.

研究成果: Article

Superconductivity

Raman scattering

superconductivity

Scattering

Polarization

200 引用 (Scopus)

Carbon-substituted MgB₂ single crystals

Lee, S., Masui, T., Yamamoto, A., Uchiyama, H. & Tajima, S., 2003 10 1, ： : Physica C: Superconductivity and its Applications. 397, 1-2, p. 7-13 7 p.

研究成果: Article

Carbon

Single crystals

Crystals

electrical resistivity

carbon

32 引用 (Scopus)

Crystal growth and characterization of MgB₂: The relation between structural and superconducting properties

Lee, S., Masui, T., Mori, H., Eltsev, Y., Yamamoto, A. & Tajima, S., 2003 2, ： : Superconductor Science and Technology. 16, 2, p. 213-220 8 p.

研究成果: Article

Crystallization

Crystal growth

crystal growth

Temperature

De Haas-van Alphen effect in single crystal MgB₂

Carrington, A., Cooper, J. R., Hussey, N. E., Meeson, P. J., Yelland, E. A., Lee, S., Yamamoto, A. & Tajima, S., 2003 5, ： : Physica C: Superconductivity and its Applications. 388-389, p. 105-106 2 p.

研究成果: Article

Orbits

Single crystals

orbits

single crystals

elementary excitations

Determination of the Fermi Surface of [Formula presented] by the de Haas–van Alphen Effect

Carrington, A., Meeson, P. J., Cooper, J. R., Balicas, L., Hussey, N. E., Yelland, E. A., Lee, S., Yamamoto, A., Tajima, S., Kazakov, S. M. & Karpinski, J., 2003 7 17, ： : Physical Review Letters. 91, 3

研究成果: Article

Fermi surfaces

orbits

electrons

electronic structure

augmentation

59 引用 (Scopus)

Determination of the Fermi surface of MgB₂ by the de Haas-van Alphen effect

Carrington, A., Meeson, P. J., Cooper, J. R., Balicas, L., Hussey, N. E., Yelland, E. A., Lee, S., Yamamoto, A., Tajima, S., Kazakov, S. M. & Karpinski, J., 2003 7 18, ： : Physical Review Letters. 91, 3

研究成果: Article

Fermi surfaces

electron phonon interactions

topology

electronic structure

orbits

19 引用 (Scopus)

Effect of heavy-ion irradiation on the pinning properties of MgB₂

Chikumoto, N., Yamamoto, A., Konczykowski, M. & Murakami, M., 2003 5, ： : Physica C: Superconductivity and its Applications. 388-389, p. 167-168 2 p.

研究成果: Article

Heavy Ions

Ion bombardment

ion irradiation

Heavy ions

heavy ions

15 引用 (Scopus)

Electronic structure of B 2pσ and pπ states in MgB₂, AlB₂, and ZrB₂ single crystals

Nakamura, J., Nasubida, S. Y., Kabasawa, E., Yamazaki, H., Yamada, N., Kuroki, K., Watanabe, M., Oguchi, T., Lee, S., Yamamoto, A., Tajima, S., Umeda, Y., Minakawa, S., Kimura, N., Aoki, H., Otani, S., Shin, S., Callcott, T. A., Ederer, D. L., Denlinger, J. D. および1人, Perera, R. C. C., 2003 8, ： : Physical Review B - Condensed Matter and Materials Physics. 68, 6, p. 645151-645155 5 p., 064515.

研究成果: Article

Electron correlations

Electronic structure

Single crystals

electronic structure

single crystals

5 引用 (Scopus)

Experimental study of electron-phonon interaction in MgB₂

Tajima, S., Masui, T., Quilty, J., Lee, S., Yamamoto, A. & Yamanaka, A., 2003 5, ： : Physica C: Superconductivity and its Applications. 388-389, p. 103-104 2 p.

研究成果: Article

Electron-phonon interactions

electron phonon interactions

Superconductivity

Raman scattering

Boron

25 引用 (Scopus)

Features of the electron density in magnesium diboride: Reconstruction from X-ray diffraction data and comparison with TB-LMTO and FPLO calculations

Tsirelson, V., Stash, A., Kohout, M., Rosner, H., Mori, H., Sato, S., Lee, S., Yamamoto, A., Tajima, S. & Grin, Y., 2003 10 1, ： : Acta Crystallographica Section B: Structural Science. 59, 5, p. 575-583 9 p.

研究成果: Article

Orbital calculations

Tin

Carrier concentration

X ray diffraction

Atoms

2002

7 引用 (Scopus)

Crystal growth of Bi₂Sr₂Ca₂Cu₃O_10+x and (Bi,Pb)₂Sr₂Ca₂Cu₃O_10+x by the KCl flux method

Lee, S., Yamamoto, A. & Tajima, S., 2002 9, ： : Journal of Materials Research. 17, 9, p. 2286-2293 8 p.

研究成果: Article

Crystallization

Crystal growth

crystal growth

Fluxes

Crystals

6 引用 (Scopus)

De Haas–van Alphen Effect in Single Crystal [Formula presented]

Yelland, E. A., Cooper, J. R., Carrington, A., Hussey, N. E., Meeson, P. J., Lee, S., Yamamoto, A. & Tajima, S., 2002 1 1, ： : Physical Review Letters. 88, 21, 1 p.

研究成果: Article

single crystals

tubes

orbits

high temperature superconductors

Fermi surfaces

107 引用 (Scopus)

de Haas-van Alphen effect in single crystal MgB₂

Yelland, E. A., Cooper, J. R., Carrington, A., Hussey, N. E., Meeson, P. J., Lee, S., Yamamoto, A. & Tajima, S., 2002 5 27, ： : Physical Review Letters. 88, 21, p. 2170021-2170024 4 p.

研究成果: Article

single crystals

electron tubes

tubes

orbits

high temperature superconductors

1 引用 (Scopus)

Effects of Zn substitution on the superconductivity and pseudogap in (formula presented) with various doping levels

Yamamoto, A., Minami, K., Hu, W. Z., Miyakita, A., Izumi, M. & Tajima, S., 2002 1 1, ： : Physical Review B - Condensed Matter and Materials Physics. 65, 10, p. 1-7 7 p.

研究成果: Article

Superconductivity

Substitution reactions

superconductivity

Doping (additives)

substitutes

33 引用 (Scopus)

Effects of Zn substitution on the superconductivity and pseudogap in HgBa₂CuO_4+δ with various doping levels

Yamamoto, A., Minami, K., Hu, W. Z., Miyakita, A., Izumi, M. & Tajima, S., 2002 3 1, ： : Physical Review B - Condensed Matter and Materials Physics. 65, 10, p. 1045051-1045057 7 p., 104505.

研究成果: Article

Superconductivity

Substitution reactions

superconductivity

Doping (additives)

substitutes

Electron density distribution in a single crystal of (formula presented) (formula presented)

Mori, H., Lee, S., Yamamoto, A., Tajima, S. & Sato, S., 2002 1 1, ： : Physical Review B - Condensed Matter and Materials Physics. 65, 9, p. 1-4 4 p.

研究成果: Article

Electronic density of states

density distribution

Single crystals

Atoms

single crystals

32 引用 (Scopus)

Electron density distribution in a single crystal of Mg_1-xB₂ [x=0.045(5)]

Mori, H., Lee, S., Yamamoto, A., Tajima, S. & Sato, S., 2002 3 1, ： : Physical Review B - Condensed Matter and Materials Physics. 65, 9, p. 925071-925074 4 p., 092507.

研究成果: Article

Electronic density of states

density distribution

Single crystals

Atoms

single crystals

5 引用 (Scopus)

Electronic state of MgB₂ superconductor

Tajima, S., Masui, T., Uchiyama, H., Quilty, J. W., Eltsev, Y., Lee, S., Yamamoto, A. & Mori, H., 2002 8, ： : Current Applied Physics. 2, 4, p. 315-319 5 p.

研究成果: Article

Boron

Electronic states

Superconducting materials

Raman scattering

Photoelectron spectroscopy

6 引用 (Scopus)

Exponential Temperature Dependence of the Penetration Depth in Single Crystal [Formula presented]

Manzano, F., Carrington, A., Hussey, N. E., Lee, S., Yamamoto, A. & Tajima, S., 2002 1 1, ： : Physical Review Letters. 88, 4, 1 p.

研究成果: Article

penetration

temperature dependence

single crystals

radio frequencies

high resolution

149 引用 (Scopus)

Exponential temperature dependence of the penetration depth in single crystal MgB₂

Manzano, F., Carrington, A., Hussey, N. E., Lee, S., Yamamoto, A. & Tajima, S., 2002 1 28, ： : Physical Review Letters. 88, 4, p. 470021-470024 4 p., 047002.

研究成果: Article

penetration

temperature dependence

single crystals

radio frequencies

high resolution

71 引用 (Scopus)

High-pressure synthesis of superconducting Nb_1-xB₂ (x = 0-0.48) with the maximum T_c = 9.2 K

Yamamoto, A., Takao, C., Masui, T., Izumi, M. & Tajima, S., 2002 12 15, ： : Physica C: Superconductivity and its Applications. 383, 3, p. 197-206 10 p.

研究成果: Article

Superconductivity

superconductivity

synthesis

Special effects

Superconducting transition temperature

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