Faculty Profiles - TANIYAMA Tomoyasu

Papers - TANIYAMA Tomoyasu

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Efficient spin injection into GaAs quantum well across Fe3O4 spin filter Reviewed

Wada E., Watanabe K., Shirahata Y., Itoh M., Yamaguchi M., Taniyama T.

APPLIED PHYSICS LETTERS Vol. 96 ( 10 ) 2010.3

Coherent manipulation of individual electron spin in a double quantum dot integrated with a micromagnet Reviewed Open Access

Obata Toshiaki, Pioro-Ladriere Michel, Tokura Yasuhiro, Shin Yun-Sok, Kubo Toshihiro, Yoshida Katsuharu, Taniyama Tomoyasu, Tarucha Seigo

PHYSICAL REVIEW B Vol. 81 ( 8 ) 2010.2

Spin polarization of electrons injected from Fe into GaAs quantum well characterized using oblique Hanle effect Reviewed

Wada Eiji, Itoh Mitsuru, Taniyama Tomoyasu, Yamaguchi Masahito

NOVEL MATERIALS AND DEVICES FOR SPINTRONICS Vol. 1183 page： 57-+ 2010

Phonon Dynamics in BiFeO3 Studied by Raman Scattering Reviewed

Shimizu Takao, Era Takuro, Taniguchi Hiroki, Fu Desheng, Taniyama Tomoyasu, Itoh Mitsuru

FERROELECTRICS Vol. 403 page： 187-190 2010

Magnetic Anisotopy of Glassy Ferromagnet/Ferroelectrics Heterostructures Reviewed

T. Taniyama, Y. Shirahata, M. Itoh, P. Sharma, M. Fukuhara, A. Inoue

Proceedings of the Visual-JW2010 page： 306-307 2010

Fe/MgO Tunnel Barrier Contact for Electrical Spin Injection into GaAs for Semiconductor Spintronics Applications Reviewed

M. M. Uddin, E. Wada, Y. Shirahata, T. Taniyama

Proceedings of National Conference on Materials Science & Technology for Sustainable Development: Bangladesh Perspective page： 42-45 2010

Hamaya K.

Physical Review Letters Vol. 102 ( 23 ) 2009.6

Low-temperature ordering in FePt films deposited by gas flow sputtering Reviewed Open Access

H. Sakuma, H. Kawano, K. Ishii, T. Taniyama

J. Magn. Soc. Jpn. Vol. 33 ( 3 ) page： 167 - 170 2009.5

Stability of ferromagnetic state of epitaxially grown ordered FeRh thin films Reviewed

Suzuki Ippei, Koike Takayoshi, Itoh Mitsuru, Taniyama Tomoyasu, Sato Tetsuya

JOURNAL OF APPLIED PHYSICS Vol. 105 ( 7 ) 2009.4

Artificially controlled magnetic domain structures in ferromagnetic dots/ferroelectric heterostructures Reviewed Open Access

Taniyama Tomoyasu, Akasaka Kyohei, Fu Desheng, Itoh Mitsuru

JOURNAL OF APPLIED PHYSICS Vol. 105 ( 7 ) 2009.4

Ferromagnetism and Electronic Structures of Nonstoichiometric Heusler-Alloy Fe3-xMnxSi Epilayers Grown on Ge(111) Reviewed International journal Open Access

K. Hamaya, H. Itoh, O. Nakatsuka, K. Ueda, K. Yamamoto, M. Itakura, T. Taniyama, T. Ono, M. Miyao

PHYSICAL REVIEW LETTERS Vol. 102 ( 13 ) page： 137204/1 - 4 2009.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC

For the study of ferromagnetic materials which are compatible with group-IV semiconductor spintronics, we demonstrate control of the ferromagnetic properties of Heusler-alloy Fe3-xMnxSi epitaxially grown on Ge(111) by tuning the Mn composition x. Interestingly, we obtain L2(1)-ordered structures even for nonstoichiometric atomic compositions. The Curie temperature of the epilayers with x approximate to 0.6 exceeds 300 K. Theoretical calculations indicate that the electronic structures of the nonstoichiometric Fe3-xMnxSi alloys become half-metallic for 0.75 <= x <= 1.5. We discuss the possibility of room-temperature ferromagnetic Fe3-xMnxSi/Ge epilayers with high spin polarization.

DOI： 10.1103/PhysRevLett.102.137204

Web of Science

Other Link： http://orcid.org/0000-0003-3683-5416

Selective Addressing of Single Electron Spins in a Semiconductor Double Quantum Dot Integrated with a Micro-Magnet Reviewed

Obata Toshiaki, Pioro-Ladriere Michel, Tokura Yasuhiro, Shin Yun-Sok, Kubo Toshihiro, Yoshida Katsuharu, Taniyama Tomoyasu, Tarucha Seigo

PHYSICS OF SEMICONDUCTORS Vol. 1199 page： 381-+ 2009

Dynamical polarization effect of nuclear spin bath dragged by electron spin resonance in double quantum dot integrated with micro-magnet Reviewed Open Access

Obata T., Pioro-Ladriere M., Tokura Y., Brunner R., Shin Y. -S., Kubo T., Yoshida K., Taniyama T., Tarucha S.

16TH INTERNATIONAL CONFERENCE ON ELECTRON DYNAMICS IN SEMICONDUCTORS, OPTOELECTRONICS AND NANOSTRUCTURES (EDISON 16) Vol. 193 2009

Synthesis and Magnetic Properties of Ba2Mn2Si2O9: the First Example of S=2 Spin-Dimer with Spin-Singlet Ground Reviewed International journal

Zhangzhen He, Myung-Hwan Wangbo, Yutaka Ueda, Yasuo Narumi, Koichi Kindo, Tomoyasu Taniyama, Mitsuru Itoh, Wendan Cheng

CHEMISTRY-AN ASIAN JOURNAL Vol. 4 ( 10 ) page： 1530 - 1535 2009

Low temperature magnetism of the S=1/2 quasi one-dimensional Ising-like anitiferromagnet BaCo2V2O8 Reviewed International journal Open Access

S. Kimura, T. Takeuchi, M. Hagiwara, K. Okunishi, Z. He, T. Taniyama, M. Itoh

25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 4 Vol. 150 ( 4 ) page： 042090/1 - 4 2009

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

We report the results of thermodynamic measurements on the quasi one-dimensional (1D) Ising-like antiferromagnet BaCo2V2O8 in the magnetic fields for H//c down to 200 mK. An appearance of a long range magnetic ordered phase is observed in the field induced region above H-c similar or equal to 3.9 T at temperature below 1.8 K. A peculiar incommensurate ordering, which reflects a quantum critical nature of S = 1/2 1D Ising-like antiferromagnet, realizes in this ordered phase.

DOI： 10.1088/1742-6596/150/4/042090

Open Access

Web of Science

J-GLOBAL

Tunneling magnetoresistance effect in a few-electron quantum-dot spin valve Reviewed International journal

K. Hamaya, M. Kitabatake, K. Shibata, M. Jung, M. Kawamura, S. Ishida, T. Taniyama, K. Hirakawa, Y. Arakawa, T. Machida

APPLIED PHYSICS LETTERS Vol. 93 ( 22 ) page： 222107/1 - 3 2008.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

We demonstrate the tunneling magnetoresistance (TMR) effect through a semiconductor quantum dot (QD) with a few electrons in a lateral QD spin-valve device. At one-to-two electron transition, only inverse TMR effect is observed, where the TMR ratio is relatively large compared with the value based on the Julliere model. When the bias window reaches near the charging energy of the QD, the inverse TMR almost disappears. These features can be interpreted in terms of spin transport via the ground state of a two-electron QD.

DOI： 10.1063/1.3042098

Longitudinal Spin Density Wave Order in a Quasi-1D Ising-like Quantum Antiferromagnet Reviewed International journal Open Access

S. Kimura, M. Matsuda, T. Masuda, S. Hondo, K. Kaneko, N. Metoki, M. Hagiwara, T. Takeuchi, K. Okunishi, Z. He, K. Kindo, T. Taniyama, M. Itoh

PHYSICAL REVIEW LETTERS Vol. 101 ( 20 ) page： 207201/1 - 4 2008.11

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC

From neutron diffraction measurements on a quasi-1D Ising-like Co2+ spin compound BaCo2V2O8, we observed an appearance of a novel type of incommensurate ordering in magnetic fields. This ordering is essentially different from the Neel-type ordering, which is expected for the classical system, and the peculiar spin structure is caused by quantum fluctuation inherent in the quantum spin chain. A Tomonaga-Luttinger liquid nature characteristic of the gapless quantum 1D system is responsible for the realization of the incommensurate ordering.

DOI： 10.1103/PhysRevLett.101.207201

Web of Science

Scopus

Other Link： http://orcid.org/0000-0003-3683-5416

Reply to Comment on "Origin of Giant Dielectric Response in Nonferroelectric CaCu3Ti4O12: Inhomogeneous Conduction Nature Probed by Atomic Force Microscopy" Reviewed International journal

Desheng Fu, Hiroki Taniguchi, Tomoyasu Taniyama, Mitsuru Itoh, Shin-ya Koshihara

CHEMISTRY OF MATERIALS Vol. 20 ( 19 ) page： 6286 - 6287 2008.10

Electrically driven single-electron spin resonance in a slanting Zeeman field Reviewed International journal Open Access

M. Pioro-Ladriere, T. Obata, Y. Tokura, Y. -S. Shin, T. Kubo, K. Yoshida, T. Taniyama, S. Tarucha

NATURE PHYSICS Vol. 4 ( 10 ) page： 776 - 779 2008.10

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

The rapid rise of spintronics and quantum information science has led to a strong interest in developing the ability to coherently manipulate electron spins(1). Electron spin resonance(2) is a powerful technique for manipulating spins that is commonly achieved by applying an oscillating magnetic field. However, the technique has proven very challenging when addressing individual spins(3-5). In contrast, by mixing the spin and charge degrees of freedom in a controlled way through engineered non-uniform magnetic fields, electron spin can be manipulated electrically without the need of high-frequency magnetic fields(6,7). Here we report experiments in which electrically driven addressable spin rotations on two individual electrons were realized by integrating a micrometre-size ferromagnet into a double-quantum-dot device. We find that it is the stray magnetic field of the micromagnet that enables the electrical control and spin selectivity. The results suggest that our approach can be tailored to multidot architecture and therefore could open an avenue towards manipulating electron spins electrically in a scalable way.

DOI： 10.1038/nphys1053

Web of Science

Scopus

Other Link： http://orcid.org/0000-0003-3683-5416

Carrier induced magnetic anomalies in Mn-doped AgGaSe(2) magnetic semiconductor Reviewed International journal

Kenji Yoshino, Aya Kinoshita, Yasuhiro Shirahata, Tetuo Ikari, Tomoyasu Taniyama

JOURNAL OF APPLIED PHYSICS Vol. 103 ( 7 ) page： 07D103/1 - 3 2008.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

Magnetic behaviors of the magnetic semiconductor Mn-doped AgGaSe(2) with no secondary phases are reported. Magnetization measurements show that Mn-doped AgGaSe(2) exhibits a superparamagnetic behavior while undoped AgGaSe(2) shows diamagnetism. Significant anomalies are also seen in the temperature dependent ac susceptibility and specific heat at 190 and 275 K. These results indicate that the substitution of Mn induces magnetism in AgGaSe(2). The origin of the magnetic behaviors is discussed on the basis of the combined results of susceptibility, specific heat, and photoluminescence.

DOI： 10.1063/1.2831500

Web of Science

J-GLOBAL

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Papers - TANIYAMA Tomoyasu