Correlated Electron Research Group (CERG), RIKEN Advanced Science Institute

## All |
## FY 2010 |
## FY 2011 |
## FY 2012 |

Publications

- * S. Nakosai, J. C. Budich, Y. Tanaka, B. Trauzettel, and N. Nagaosa.

"Majorana bound states and non-local spin correlations in a quantum wire on an unconventional superconductor"

Phys. Rev. Lett. 110, 117002 (12 March 2013) - * M. Kubota, K. Shibuya, Y. Tokunaga, F. Kagawa, A. Tsukazaki, Y. Tokura, M. Kawasaki

"Systematic control of stress-induced anisotropy in pseudomorphic iron garnet thin films"

J. Magn. Magn. Mater. 339, 63 (07 March 2013) - * M. Sakano, M. S. Bahramy, A. Katayama, T. Shimojima, H. Murakawa, Y. Kaneko, W. Malaeb, S. Shin, K. Ono, H. Kumigashira, R. Arita, N. Nagaosa,
H. Y. Hwang, Y. Tokura, and K. Ishizaka

"Strongly Spin-Orbit Coupled Two-Dimensional Electron Gas Emerging near the Surface of Polar Semiconductors"

Phys. Rev. Lett. 110, 107204 (07 March 2013) - * Shinichi Itoh, Yasuo Endoh, Tetsuya Yokoo, Daichi Kawana, Yoshio Kaneko, Yoshinori Tokura, and Masaki Fujita

"Neutron Brillouin Scattering with Pulsed Spallation Neutron Source —Spin-Wave Excitations from Ferromagnetic Powder Samples—"

J. Phys. Soc. Jpn. 82, 043001 (06 March 2013) - * Sachio Horiuchi, Reiji Kumai, & Yoshinori Tokura

"High-Temperature and Pressure-Induced Ferroelectricity in Hydrogen-Bonded Supramolecular Crystals of Anilic Acids and 2, 3-Di(2-pyridinyl)pyrazine"

J. Am. Chem. Soc. 135(11), 4492-4500 (28 February 2013) - * P. A. Lee and N. Nagaosa

"Proposal to use neutron scattering to access scalar spin chirality fluctuations in kagome lattices"

Phys. Rev. B 87, 064423 (28 February 2013) - * Y. Yamaki, Y. Yamasaki, H. Nakao, Y. Murakami, Y. Kaneko, and Y. Tokura

"X-ray photoinduced persistent and bidirectional phase transition enabled by impurity doping in layered manganite"

Phys. Rev. B 87, 081107(R) (28 February 2013) - * C. Bell, M. S. Bahramy, H. Murakawa, J. G. Checkelsky, R. Arita,Y. Kaneko, Y. Onose, N. Nagaosa, Y. Tokura, and H. Y. Hwang

"Shubnikov–de Haas oscillations in the bulk Rashba semiconductor BiTeI"

Phys. Rev. B 87, 081109(R) (28 February 2013) - * Bohm-Jung Yang, Mohammad Saeed Bahramy & Naoto Nagaosa

"Topological protection of bound states against the hybridization"

Nature Communications 4, 1524 (26 February 2013) - * T. Makino, Y. Segawa, A. Tsukazaki, H. Saito, S. Takeyama, S. Akasaka, K. Nakahara,

and M. Kawasaki

"Magneto-photoluminescence of charged excitons from Mg_{x}Zn_{1−x}O/ZnO heterojunctions"

Phys. Rev. B 87, 085312 (25 February 2013) - * V. Kocsis, S. Bordács, D. Varjas, K. Penc, A. Abouelsayed, C. A. Kuntscher, K. Ohgushi, Y. Tokura, I. Kézsmárki

"Magnetoelasticity in ACr2O4 spinel oxides (A = Mn, Fe, Co, Ni, and Cu)"

Phys. Rev. B 87, 064416 (20 February 2013) - * Bohm-Jung Yang, Mohammad Saeed Bahramy, Ryotaro Arita, Hiroki Isobe, Eun-Gook Moon, and Naoto Nagaosa

"Theory of Topological Quantum Phase Transitions in 3D Noncentrosymmetric Systems"

Phys. Rev. Lett. 110, 086402 (19 February 2013) - * J. Iwasaki, M. Mochizuki, and N. Nagaosa

"Universal current-velocityrelation of skyrmion motion in chiral magnets"

Nature Communications 4, 2442 (12 February 2013) - * P.-H. Xiang, S. Asanuma, H. Yamada, H. Sato, I. H. Inoue, H. Akoh, A. Sawa, M. Kawasaki, and Y. Iwasa

"Electrolyte-Gated SmCoO3 Thin-Film Transistors Exhibiting Thickness-Dependent Large Switching Ratio at Room Temperature"

Advanced Materials 25(05 February 2013) - * T. Kurumaji, S. Seki, S. Ishiwata, H. Murakawa, Y. Kaneko, and Y. Tokura

"Magnetoelectric responses induced by domain rearrangement and spin structural change in triangular-lattice helimagnets NiI_{2}and CoI_{2}"

Phys. Rev. B 87, 014429 (25 January 2013) - * Sachio Horiuchi, Fumitaka Kagawa, Kensuke Hatahara, Kensuke Kobayashi, Reiji Kumai,

Youichi Murakami & Yoshinori Tokura

"Above-room-temperature ferroelectricity and antiferroelectricity in benzimidazoles"

Nature Communications 3, 1308 (18 December 2012) - * Y. Kasahara, Y. Oshima, J. Falson, Y. Kozuka, A. Tsukazaki, M. Kawasaki, Y. Iwasa

"Correlation-Enhanced Effective Mass of Two-Dimensional Electrons in Mg_{x}Zn_{1-x}O/ZnO Heterostructures"

Phys. Rev. Lett. 109, 246401 (10 December 2012) - * K. Sawabe, M. Imakawa, M. Nakano, T. Yamao, S. Hotta, Y. Iwasa, T. Takenobu,

"Current-Confinement Structure and Extremely High Current Density in Organic Light-Emitting Transistors"

Adv. Mater. 24, 6141-6146 (04 December 2012) - * J.T. Ye, Y. J. Zhang, R. Akashi, M. S. Bahramy, R. Arita, Y. Iwasa

"Superconducting Dome in a Gate-Tuned Band Insulator"

Science 338, 1193-1196 (30 November 2012) - * N. Nagaosa, X. Z. Yu and Y. Tokura

"Gauge fields in real and momentum spaces in magnets: monopoles and skyrmions"

Phil. Trans. R. Soc. A, 370, 5806-5819 (19 November 2012) - * Y. Shiomi, S. Iguchi, and Y. Tokura

"Emergence of topological Hall effect from fanlike spin structure as modified by Dzyaloshinsky-Moriya interaction in MnP"

Phys. Rev. B 86, 180404(R) (15 November 2012) - * N. Kanazawa, J.-H. Kim, D. S. Inosov, J. S. White, N. Egetenmeyer, J. L. Gavilano, S. Ishiwata,

Y. Onose, T. Arima, B. Keimer, and Y. Tokura

"Possible skyrmion-lattice ground state in the B20 chiral-lattice magnet MnGe as seen via small-angle neutron scattering"

Phys. Rev. B 86, 134425 (25 October 2012) - * M.S. Bahramy, P.D.C King, A. de la Torre, J. Chang, M. Shi, L. Patthey, G. Balakrishnan, Ph. Hofmann, R. Arita, N. Nagaosa & F. Baumberger

"Emergent quantum confinement at topological insulator surfaces"

Nature Communications 3, 1159 (23 October 2012) - * H. Isobe and N. Nagaosa

"Theory of a quantum critical phenomenon in a topological insulator: (3+1)-dimensional quantum electrodynamics in solids"

Phys. Rev. B 86, 165127 (19 October 2012) - * M. Uchida, Y. Yamasaki, Y. Kaneko, K. Ishizaka, J. Okamoto, H. Nakao, Y. Murakami,

and Y. Tokura

"Pseudogap-related charge dynamics in the layered nickelate R_{2−x}Sr_{x}NiO_{4}(x∼1)"

Phys. Rev. B 86, 165126-1 - 165126-6 (19 October 2012) - * Farzad Mahfouzi, Naoto Nagaosa, and Branislav K. Nikolic

"Spin-Orbit Coupling Induced Spin-Transfer Torque and Current Polarization in Topological-Insulator/Ferromagnet Vertical Heterostructures"

Phys. Rev. Lett. 109, 166602 (17 October 2012) - * L. Demko, G. A. H. Schober, V. Kocsis, M. S. Bahramy, H. Murakawa, J. S. Lee, I. Kezsmarki, R. Arita, N. Nagaosa, and Y. Tokura

"Enhanced Infrared Magneto-Optical Response of the Nonmagnetic Semiconductor BiTeI Driven by Bulk Rashba Splitting"

Phys. Rev. Lett. 109, 167401 (15 October 2012) - * H. Isobe and N. Nagaosa

"Renormalization Effects on Quasi-Two-Dimensional Organic Conductor α-(BEDT-TTF)_{2}I_{3}"

J. Phys. Soc. Jpn. 81,113704 (11 October 2012) - * M. Garganourakis, V. Scagnoli, S. W. Huang, U. Staub, H. Wadati, M. Nakamura, V. A. Guzenko, M. Kawasaki and Y. Tokura

"Imprinting Magnetic Information in Manganites with X Rays"

Phys. Rev. Lett. 109, 157203 (09 October 2012) - * Y. Nii, H. Sagayama, T. Arima, S. Aoyagi, R. Sakai, S. Maki, E. Nishibori, H. Sawa, K. Sugimoto, H. Ohsumi, M. Takata

"Orbital structures in spinel vanadates AV_{2}O_{4}(A = Fe, Mn)"

Phys. Rev. B 86, 125142 (28 September 2012) - * K. Ueda, J. Fujioka, Y. Takahashi, T. Suzuki, S. Ishiwata, Y. Taguchi, and Y. Tokura

"Variation of Charge Dynamics in the Course of Metal-Insulator Transition for Pyrochlore-Type Nd_{2}Ir_{2}O_{7}"

Phys. Rev. Lett. 109, 136402 (27 September 2012) - * Masashi Kawasaki & Yoshihiro Iwasa

"Electronics: ‘Cut and stick’ ion gels"

Nature 489, 510–511 (26 September 2012) - * T. Kiss, A. Chainani, H. M. Yamamoto, T. Miyazaki, T. Akimoto, T. Shimojima, K. Ishizaka, S. Watanabe, C.–T. Chen, A. Fukaya, R. Kato, S. Shin,

"Quasiparticles and Fermi liquid behavior in an organic metal"

Nature Communications 3, 1089 (25 September 2012) - * Jun'ichi Ozaki, Masaki Tezuka, and Norio Kawakami

"Collision of one-dimensional fermion clusters"

Phys. Rev. A 86, 033621 (18 September 2012) - * Masao Nakamura, Masashi Kawasaki, and Yoshinori Tokura

"e_{g}-level splitting in a layered perovskite manganite as revealed by charge modulation spectroscopy"

Phys. Rev. B 86, 125127 (18 September 2012) - * Y. Kozuka, H. Seki, T. Fujita, S. Chakraverty, K. Yoshimatsu, H. Kumigashira, M. Oshima, M. Bahramy, R. Arita, M. Kawasaki

Epitaxially Stabilized EuMoO3: A New Itinerant Ferromagnet

Chem. Mater., 24 (19), 3746–3750 (14 September 2012) - * D. Asahi and N. Nagaosa

"Topological indices, defects, and Majorana fermions in chiral superconductors"

Phys. Rev. B 86, 100504 (14 September 2012) - * Masashi Kubota, Atsushi Tsukazaki, Fumitaka Kagawa, Keisuke Shibuya, Yusuke Tokunaga, Masashi Kawasaki, and Yoshinori Tokura

"Stress-Induced Perpendicular Magnetization in Epitaxial Iron Garnet Thin Films"

Appl. Phys. Express 5, 103002 (13 September 2012) - * H. Sakai, J. Fujioka, T. Fukuda, M. S. Bahramy, D. Okuyama, R. Arita, T. Arima, A. Q. R. Baron, Y. Taguchi, and Y. Tokura

"Soft phonon mode coupled with antiferromagnetic order in incipient-ferroelectric Mott insulators Sr_{1−x}Ba_{x}MnO_{3}"

Phys. Rev. B 86, 104407 (05 September 2012) - * Y. Kozuka, J. Falson, Y. Segawa, T. Makino, A. Tsukazaki, and M. Kawasaki

"Precise calibration of Mg concentration in Mg_{x}Zn_{1-X}O thin films grown on ZnO substrates"

J. Appl. Phys. 112, 043515 (29 August 2012) - * Y. W. Long, Y. Kaneko, S. Ishiwata, Y. Tokunaga, T. Matsuda, H. Wadati, Y. Tanaka, S. Shin, Y. Tokura, and Y. Taguchi

"Evolution of magnetic phases in single crystals of SrFe_{1−x}Co_{x}O_{3}solid solution"

Phys. Rev. B 86, 064436 (27 August 2012) - * S. Bordács, I. Kézsmárki, D. Szaller, L. Demkó, N. Kida, H. Murakawa, Y. Onose, R. Shimano, T. Rõõm, U. Nagel,

S. Miyahara, N. Furukawa, & Y. Tokura

"Chirality of matter shows up via spin excitations"

Nature Physics doi:10.1038/nphys2387 (26 August 2012) - * Joseph G. Checkelsky, Jianting Ye, Yoshinori Onose, Yoshihiro Iwasa & Yoshinori Tokura

"Dirac-fermion-mediated ferromagnetism in a topological insulator"

Nature Physics doi:10.1038/nphys2388 (19 August 2012) - * Yusuke Tokunaga, Yasujiro Taguchi, Taka-hisa Arima & Yoshinori Tokura

"Electric-field-induced generation and reversal of ferromagnetic moment in ferrites"

Nature Physics doi:10.1038/nphys2405 (19 August 2012) - * M. Sakano, J. Miyawaki, A. Chainani, Y. Takata, T. Sonobe, T. Shimojima, M. Oura, S. Shin,

M. S. Bahramy, R. Arita, N. Nagaosa, H. Murakawa, Y. Kaneko, Y. Tokura, and K. Ishizaka

"Three-dimensional bulk band dispersion in polar BiTeI with giant Rashba-type spin splitting"

Phys. Rev. B 86, 085204 (16 August 2012) - * S. Seki, S. Ishiwata, and Y. Tokura

"Magnetoelectric nature of skyrmions in a chiral magnetic insulator Cu_{2}OSeO_{3}"

Phys. Rev. B 86, 060403(R) (09 August 2012) - * X.Z. Yu, N. Kanazawa, W.Z. Zhang, T. Nagai, T. Hara, K. Kimoto, Y. Matsui,

Y. Onose & Y. Tokura

"Skyrmion flow near room temperature in an ultralow current density"

Nature Communications 3, 988 (07 August 2012) - * T. Makino, F. Liu, T. Yamasaki, Y. Kozuka, K. Ueno, A. Tsukazaki, T. Fukumura, Y. Kong, and M. Kawasaki

"Ultrafast optical control of magnetization in EuO thin films"

Phys. Rev. B 86, 064403 (02 August 2012) - * A. Shitade and N. Nagaosa

"Anomalous Hall Effect in Ferromagnetic Metals: Role of Phonons at Finite Temperature"

J. Phys. Soc. Jpn. 81, 083704 (01 August 2012) - * J. S. Lee, Hal. Q. Yamamoto, M. Uchida, and Y. Tokura

"Spin and charge states of Co in half-doped layered cobaltates La_{1.5}Ca_{0.5}CoO_{4}and La_{1.5}Sr_{0.5}CoO_{4}"

Phys. Rev. B 86, 045319 (27 July 2012) - * Sunao Shimizu, Ryutaro Yoshimi, Takafumi Hatano, Kei S. Takahashi, Atsushi Tsukazaki, Masashi Kawasaki, Yoshihiro Iwasa, and Yoshinori Tokura

"Gate control of surface transport in MBE-grown topological insulator (Bi_{1−x}Sb_{x})_{2}Te_{3}thin films"

Phys. Rev. B 86, 045319 (27 July 2012) - * M. Nakano, K. Shibuya, D. Okuyama, T. Hatano, S. Ono, M. Kawasaki, Y. Iwasa & Y. Tokura

"Collective bulk carrier delocalization driven by electrostatic surface charge accumulation"

Nature 487, 459–462 (26 July 2012) - * Y. Onose, Y. Okamura, S. Seki, S. Ishiwata, and Y. Tokura

"Observation of Magnetic Excitations of Skyrmion Crystal in a Helimagnetic Insulator Cu_{2}OSeO_{3}"

Phys. Rev. Lett. 109, 037603 (20 July 2012) - * Zhigao Sheng, Masao Nakamura, Fumitaka Kagawa, Masashi Kawasaki & Yoshinori Tokura

"Dynamics of multiple phases in a colossal-magnetoresistive manganite as revealed by dielectric spectroscopy"

*Nature Communications*3, 944 ( 10 July 2012) - * Y. Yomogida, J. Pu, H. Shimotani, S. Ono, S. Hotta, Y. Iwasa, T. Takenobu

"Ambipolar organic single-crystal transistors based on ion gels"

*Adv. Mater.*DOI: 10.1002/adma.201200655 ( published online: 22 June 2012 ) - * S. Seki, J.-H. Kim, D. S. Inosov, R. Georgii, S. Ishiwata, B. Keimer, and Y. Tokura

"Formation and rotation of skyrmion crystal in the chiral-lattice insulator Cu_{2}OSeO_{3}"

*Phys. Rev. B*85, 220406 ( 22 June 2012) - * Y. Kasahara, Y. Takeuchi, Y. Iwasa

"Bulk superconductivity and fully gapped superconducting state in Ba-doped phenanthrene"

*Phys. Rev. B*85, 214520 ( 20 June 2012) - * F. Liu, T. Makino, T. Yamasaki, K. Ueno, A. Tsukazaki, T. Fukumura, Y. Kong, and M. Kawasaki

"Ultrafast Time-Resolved Faraday Rotation in EuO Thin Films"

*Phys. Rev. Lett.*108, 257401 ( 19 June 2012) - * N. Sugimoto and N. Nagaosa

"Spin-Orbit Echo"

*Science*336, 1413 ( 15 June 2012) - * G. A. H. Schober, H. Murakawa, M. S. Bahramy, R. Arita, Y. Kaneko, Y. Tokura, and N. Nagaosa

"Mechanisms of Enhanced Orbital Dia- and Paramagnetism: Application to the Rashba Semiconductor BiTeI"

*Phys. Rev. Lett.*108, 247208 ( 13 June 2012) - * F. Kagawa, K. Hatahara, S. Horiuchi, and Y. Tokura

"Domain-wall dynamics coupled to proton motion in a hydrogen-bonded organic ferroelectric"

*Phys. Rev. B*85, 220101(R) ( 08 June 2012) - * X. Yu, M. Mostovoy, Y. Tokunaga, W. Zhang, K. Kimoto, Y. Matsui, Y. Kaneko, N. Nagaosa, and Y. Tokura

"Magnetic stripes and skyrmions with helicity reversals"

*Proc. Nat. Acad. Sci.*109, 8856-8860 ( 05 June 2012) - * Kensuke Kobayashi, Sachio Horiuchi, Reiji Kumai, Fumitaka Kagawa, Youichi Murakami, and Yoshinori Tokura

"Electronic Ferroelectricity in a Molecular Crystal with Large Polarization Directing Antiparallel to Ionic Displacement"

*Phys. Rev. Lett.*108, 237601 ( 04 June 2012) - * M. Sato, H. Katsura and N. Nagaosa

"Theory of Raman Scattering in One-Dimensional Quantum Spin-1/2 Antiferromagnets"

*Phys. Rev. Lett.*108, 237401 ( 04 June 2012) - * H. Murakawa, Y. Onose, S. Miyahara, N. Furukawa, and Y. Tokura

"Comprehensive study of the ferroelectricity induced by the spin-dependent d- p hybridization mechanism in Ba_{2}XGe_{2}O_{7}(X = Mn, Co, and Cu)"

*Phys. Rev. B*85, 174106 ( 14 May 2012) - * L. Demkó, S. Bordács, T. Vojta, D. Nozadze, F. Hrahsheh, C. Svoboda, B. Dóra, H. Yamada, M. Kawasaki, Y. Tokura, and I. Kézsmárki

"Disorder Promotes Ferromagnetism: Rounding of the Quantum Phase Transition in Sr_{1-x}Ca_{x}RuO_{3}"

*Phys. Rev. Lett.*108, 185701 ( 3 May 2012) - * D. Maryenko, J. Falson, Y. Kozuka, A. Tsukazaki, M. Onoda, H. Aoki, and M. Kawasaki

"Temperature-Dependent Magnetotransport around ν=1/2 in ZnO Heterostructures"

*Phys. Rev. Lett.*108, 186803 ( 1 May 2012) - * J. Fujioka, S. Ishiwata, Y. Kaneko, Y. Taguchi, and Y. Tokura

"Variation of charge dynamics upon the helimagnetic and metal-insulator transitions for perovskite AFeO_{3}(A = Sr and Ca)"

*Phys. Rev. B*85, 155141 ( 27 April 2012) - * S. Seki, X. Z. Yu, S. Ishiwata, Y. Tokura

"Observation of Skyrmions in a Multiferroic Material"

*Science*336, no. 6078, pp. 198-201 ( 13 April 2012) - * K. Ueda, S. Iguchi, T. Suzuki, S. Ishiwata, Y. Taguchi, and Y. Tokura

"Topological Hall Effect in Pyrochlore Lattice with Varying Density of Spin Chirality"

*Phys. Rev. Lett.*108, 156601 ( 09 April 2012) - * J. S. Lee, K. Shibuya, M. Kawasaki, and Y. Tokura

"Optical investigation of metal-insulator transitions in V_{1−x}W_{x}O_{2}(0 ≤ x ≤ 0.33)"

*Phys. Rev. B*85, 155110 ( 06 April 2012) - * S. Nakosai, Y. Tanaka, and N. Nagaosa

"Topological Superconductivity in Bilayer Rashba System"

*Phys. Rev. Lett.*108, 147003 ( 05 April 2012) - * T. Ideue, Y. Onose, H. Katsura, Y. Shiomi, S. Ishiwata, N. Nagaosa, and Y. Tokura

"Effect of lattice geometry on magnon Hall effect in ferromagnetic insulators"

*Phys. Rev. B*85, 134411 ( 04 April 2012) - * Z. Y. Chen, H. T. Yuan, Y. F. Zhan, K. Nomura, T. Gao, Y. Gao, H. Shimotani, Z. F. Liu, Y. Iwasa

"Tunable spin-orbit interaction in trilayer graphene exemplified in electric-double-layer transistors"

*Nano Lett.*12, 2212-2216 ( 03 April 2012)