IMR, Tohoku University

Recent research topics

デラフォサイト型層状酸化物の薄膜物性研究
Highly conductive PdCoO₂ ultrathin films for transparent electrodes
T. Harada, K. Fujiwara, A. Tsukazaki
APL Materials 6, 046107 (2018).

Electric dipole effect in PdCoO₂/ β-Ga₂O₃ Schottky diodes for high temperature operation
T. Harada, S. Ito, A. Tsukazaki
Science Advances 5, eaax5733 (2019).

水溶性テンプレートによる微細化とデバイス特性評価
プロセスの詳細
A versatile patterning process based on easily soluble sacrificial bilayers
T. Harada and A. Tsukazaki
AIP Advances 7, 085011 (2017).

Microfabrication of SrRuO₃ thin films on various oxide substrates using LaAlO₃/BaO_x sacrificial bilayers
T. Harada and A. Tsukazaki
Proc. SPIE 10533, 105330X (2018).

応用例
Critical current enhancement driven by suppression of superconducting fluctuation in ion-gated ultrathin FeSe
T. Harada, J. Shiogai, T. Miyakawa, T. Nojima, A. Tsukazaki
Superconductor Science and Technology 31, 055003 (2018).

Publication list

26. Determination of the phase coherence length of PdCoO₂ nanostructures
T. Harada, P. Bredol, H. Inoue, S. Ito, J. Mannhart, A. Tsukazaki
arXiv:2007.03146.

25. Inhomogeneous interface dipole effect at the Schottky junctions of PdCrO₂ on β-Ga₂O₃ (201) substrates
T. Miyakawa, T. Harada, S. Ito, A. Tsukazaki
Journal of Applied Physics 128, 025302 (2020).

24. Dynamic characteristics of PdCoO₂/β-Ga₂O₃ Schottky junctions
T. Harada, A. Tsukazaki
Applied Physics Letters 116, 232104 (2020).

23. Control of Schottky barrier height in metal/β-Ga₂O₃ junctions by insertion of PdCoO₂ layers
T. Harada, A. Tsukazaki
APL Materials 8, 041109 (2020).
[Selected for Featured Article and Most read]

22. Anomalous Hall effect at the spontaneously electron-doped polar surface of PdCoO₂ ultrathin films
T. Harada, K. Sugawara, K. Fujiwara, M. Kitamura, S. Ito, T. Nojima, K. Horiba, H. Kumigashira, T. Takahashi, T. Sato, A. Tsukazaki
Physical Review Research 2, 013282 (2020).

21. Electric dipole effect in PdCoO₂/β-Ga₂O₃ Schottky diodes for high temperature operation
T. Harada, S. Ito, A. Tsukazaki
Science Advances 5, eaax5733 (2019).
[プレス発表] 日経新聞電子版、PC Watch、Yahoo!ニュース、EE times、財経新聞、NewsPicks 他多数掲載
[記事掲載] 矢野経済研究所 Yano E-plus 3月号 (2020)

20. Ferromagnetism and conductivity in atomically thin SrRuO₃
H. Boschker, T. Harada, T. Asaba, R. Ashoori, A. V. Boris, H. Hilgenkamp, C. R. Hughes, M. E. Holtz, L. Li, D. A. Muller, H. Nair, Reith, X. Renshaw Wang, D. G. Schlom, A. Soukiassian, and J. Mannhart
Physical Review X 9, 011027 (2019).

19. Highly conductive PdCoO₂ ultrathin films for transparent electrodes
T. Harada, K. Fujiwara, A. Tsukazaki
APL Materials 6, 046107 (2018).
[Selected for Editor's picks and Most read]

18. Critical current enhancement driven by suppression of superconducting fluctuation in ion-gated ultrathin FeSe
T. Harada, J. Shiogai, T. Miyakawa, T. Nojima, A. Tsukazaki
Superconductor Science and Technology 31, 055003 (2018).

17. Enhancement of superconducting transition temperature in FeSe electric-double-layer transistor with multivalent ionic liquids
T. Miyakawa, J. Shiogai, S. Shimizu, M. Matsumoto, Y. Ito, T. Harada, K. Fujiwara, T. Nojima, Y. Itoh, T. Aida, Y. Iwasa, A. Tsukazaki
Physical Review Materials 2, 031801(R) (2018).

16. Microfabrication of SrRuO₃ thin films on various oxide substrates using LaAlO₃/BaO_x sacrificial bilayers
T. Harada and A. Tsukazaki
Proc. SPIE 10533, 105330X (2018).

15. A versatile patterning process based on easily soluble sacrificial bilayers
T. Harada and A. Tsukazaki
AIP Advances 7, 085011 (2017).

14. Superconducting coupling across a spin-filtering manganite tunnel barrier with magnetic disorder
T. Harada, M. Matvejeff, R. Takahashi, and M. Lippmaa
EPL 115, 67005 (2016).

13. Hydrostatic pressure response of an oxide-based two-dimensional electron system
J. Zabaleta, V. S. Borisov, R. Wanke, H. O. Jeschke, S. C. Parks, B. Baum, A. Teker, T. Harada, K. Syassen, T. Kopp, N. Pavlenko, R. Valentí, and J. Mannhart
Physical Review B 93, 235117 (2016).

12. Field-effect transistors with submicrometer gate lengths fabricated from LaAlO₃-SrTiO₃-based heterostructures
C. Woltmann, T. Harada, H. Boschker, V. Srot, P. A. van Aken, H. Klauk, and J. Mannhart
Physical Review Applied 4, 064003 (2015).

11. Nonmagnetic Sc substitution in a perovskite ferromagnetic insulator Pr_0.8Ca_0.2MnO₃
T. Harada, R. Takahashi, and M. Lippmaa
Journal of the Physical Society of Japan 82, 014801 (2013).

10. Spectroscopic studies on the electronic and magnetic states of Co-doped perovskite manganite Pr_0.8Ca_0.2Mn_1-yCo_yO₃ thin films
K. Yoshimatsu, H. Wadati, E. Sakai, T. Harada, Y. Takahashi, T. Harano, G. Shibata, K. Ishigami, K. Kadono, T. Koide, T. Sugiyama, E. Ikenaga, H. Kumigashira, M. Lippmaa, M. Oshima, and A. Fujimori
Physical Review B 88, 174423 (2013).

9. Large tunnel magnetoresistance in epitaxial oxide spin-filter tunnel junctions
T. Harada, I. Ohkubo, M. Lippmaa, Y. Sakurai, Y. Matsumoto, S. Muto, H. Koinuma, and M. Oshima
Advanced Functional Materials 22, 4471 (2012).
[Highlighted in Back Cover]


8. Spin filter tunnel junction with matched Fermi surfaces
T. Harada, I. Ohkubo, M. Lippmaa, Y. Sakurai, Y. Matsumoto, S. Muto, H. Koinuma, and M. Oshima
Physical Review Letters 109, 076602 (2012).

7. Modulation of the ferromagnetic insulating phase in Pr_0.8Ca_0.2MnO₃ by Co substitution
T. Harada, I. Ohkubo, M. Lippmaa, Y. Matsumoto, M. Sumiya, H. Koinuma, and M. Oshima
Physica Status Solidi RRL, 5, 34 (2011).

6. Device size dependence of resistance switching performance in metal/manganite/metal trilayers
G. Sugano, I. Ohkubo, T. Harada, T. Ohnishi, M. Lippmaa, Y. Matsumoto, H. Koinuma, M. Oshima
Materials Science and Engineering B 173, 3 (2010).

5. Dependence of magnetic properties on laser ablation conditions for epitaxial La_0.6Sr_0.4MnO₃ thin films grown by pulsed laser deposition
T. Harada, I. Ohkubo, and M. Oshima
Materials transactions 50, 1081 (2009).

4. Field-induced resistance switching at metal/perovskite manganese oxide interface
I. Ohkubo, K. Tsubouchi, T. Harada, H. Kumigashira, K. Itaka, Y. Matsumoto, T. Ohnishi, M. Lippmaa, H. Koinuma, and M. Oshima
Materials Science and Engineering B 148, 13 (2008).

3. Modification of reflection high-energy electron diffraction system for in-situmonitoring of oxide epitaxy at high oxygen pressure
K. Tsubouchi, I. Ohkubo, T. Harada, H. Kumigashira, Y. Matsumoto, T. Ohnishi, M. Lippmaa, H. Koinuma, and M. Oshima
Materials Science and Engineering B 148, 16 (2008).

2. Trap-controlled space-charge-limited current mechanism in resistance switching at Al/Pr_0.7Ca_0.3MnO₃ interface
T. Harada, I. Ohkubo, K. Tsubouchi, H. Kumigashira, T. Ohnishi, M. Lippmaa, Y. Matsumoto, H. Koinuma, and M. Oshima
Applied Physics Letters 92, 222113 (2008).
[プレス発表]日刊工業新聞掲載 (2008/6/7)

1. Spectroscopic visualization of vortex flows using dye-containing nanofibers
A. Tsuda, M. A. Alam, T. Harada, T. Yamaguchi, N. Ishii, and T. Aida
Angewandte Chemie International Edition, 46, 8198 (2007).

Invited talks (After 2015)

[1] Properties of single RuO₂ layer embedded in SrTiO₃”
T. Harada,IEEE International Magnetics Conference, Beijing, May 14, 2015 [招待講演]

[2] “酸化物界面を利用したナノデバイス開発”
原田尚之, 酸化物研究の新機軸に向けた学際討論会, 東北大学, 2017年1月13日 [招待講演]

[3] “Enhancement of critical-current density against thickness reduction in two-dimensional superconductivity of FeSe EDLT”
T. Harada, CEMS Topical Meeting on Emergent 2D Materials, Wako, Japan, July 21, 2017 [招待講演]

[4] “Microfabrication process using LaAlO₃/BaO_x water-soluble sacrificial bilayers”
T. Harada, and A. Tsukazaki, SPIE Photonics West, Sanfrancisco, USA, January 30, 2018 [招待講演]

[5] “機能性薄膜の汎用的微細化プロセスとデバイス開発”
原田 尚之, Woltmann Carsten, Wittlich Pascal, Mannhart Jochen, 塚﨑 敦, 第65回応用物理学会春季学術講演会, 早稲田大学, 2018年3月17日 [招待講演]

[6] “Surface and interface phenomena in PdCoO₂ ultrathin films”
T. Harada, Max-Planck-Institute Stuttgart Research seminar, Stuttgart, Germany, Oct. 2018 [招待講演]

[7] “Thin-film growth of PdCoO₂: a layered oxide as conductive as gold”
T. Harada, International Conference on Crystal Growth and Epitaxy-19, Colorado, USA, August 2019 [招待講演]

[8] “PdCoO₂ thin film growth toward quantum electronics”
T. Harada, 2nd International Workshop on Nanoelectronics, Ringberg, Germany, October 2019 [招待講演]

[9]“剥離・転写技術の新展開とデバイス作製への応用例”
原田 尚之, 電気学会フレキシブルセラミックスコーティング技術調査専門委員会研究会 , 2019年11月　[招待講演]