Research Interests

• Electric field-effect modulation of physical properties by using electric double layer transistor, focusing on insulator to superconductor transition.
• Oxide semiconductor. Mother materials for superconductors, such as SrTiO₃ and KTaO ₃

  "Discovery of superconductivity in KTaO₃ by electrostatic carrier doping", K. Ueno, et al., Nature Nanotechnology , in press.
  "Electric Field Induced Superconductivity in an Insulator", K. Ueno, et al., Nature Materials 7, 855 (2008).
  

• Spintronics application of oxide ferromagnetic materials. Electric field-effect modulation of room-temperature ferromagnetism in transparent semiconductor, Co doped TiO₂. Thin film growth and physical properties for strongly correlated electron systems such as iron oxides and manganese oxides.

  "Electrically-induced ferromagnetism at room temperature in cobalt-doped titanium dioxide" Y. Yamada, K. Ueno, et al., Science, , in press.
  "Anomalous Hall effect in anatase Ti_1-xCo_xO_2-δ at low temperature regime", K. Ueno, et al.,Applied Physics Letters, 90, 72103 (2007).
  "Anomalous Hall effect in anatase Ti_1-xCo_xO_2-δ above room temperature", K. Ueno, et al., Journal of Applied Physics 103, 07D114 (2008).
  

Education

1995.4 - 1999. 3

Department of applied chemistry, faculity of engineering, the university of Tokyo, Bachelor of Engineering (supervised by Prof. K. Kitazawa)

1999.4 - 2001.1

Department of advanced materials science, graduate school of frontier science, the university of Tokyo, Master of Science.

2001.4 - 2004.1

Department of advanced materials science, graduate school of frontier science, the university of Tokyo, Doctor of Science. (supervisedby Prof. H. Takagi)
Thesis "Field-effect transistor Based on Perovskite Oxides"

Professional carrier

2001.4 - 2004.3

Correlated electron research center, National institute of advanced industrial science and technology

2004.4 - 2008.3

Postdoctal researcher, Institute for Materials Research, Tohoku University (Kawasaki laboratory)

2008.4 - 2011.3

Assistant Professor, WPI-AIMR, Tohoku University (Kawasaki laboratory)

2011.3 -

Associate Professor, Department of Basic Sciences, Graduate School of Arts and Sciences. The University of Tokyo

Publications
Research Papers

2017

1. "Electric field control of magnetic anisotropy in a Co/Pt bilayer deposited on a high-κ SrTiO₃"
   S. Nakazawa, A. Obinata, D. Chiba, K. Ueno,
   Appl. Phys. Lett., 110, 062406(2017).doi: http://dx.doi.org/10.1063/1.4976028

   2015

2. "Real-Space Observation of Short-Period Cubic Lattice of Skyrmions in MnGe"
   Y. Iguchi, S. Uemura, K. Ueno, Y. Onose,
   Phys. Rev. B, 92, 184419(2015).doi:10.1103/PhysRevB.92.184419

   2014

3. "Field-induced superconductivity in electric double layer transistors"
   K. Ueno, H. Shimotani, H. T. Yuan, J. T. Ye, M. Kawasaki, Y. Iwasa
   J. Phys. Soc. Jpn., 83, 032001 (2014). doi:10.7566/JPSJ.83.032001
   
4. "Effective thickness of two-dimensional superconductivity in a tunable triangular quantum well of SrTiO₃"
   K. Ueno, T. Nojima, S. Yonezawa, M. Kawasaki, Y. Iwasa, Y. Maeno
   Phys. Rev. B 89, 020508 (R) (2014). doi:10.1103/PhysRevB.89.020508
5. "Full determination of individual reconstructed atomic columns in intermixed heterojunctions"
   Z. Wang, M. Saito, C. Chen, Y. Matsubara, K. Ueno, M. Kawasaki, Y.Ikuhara
   Nano Lett. 14 6584 (2014). doi:10.1021/nl503212j
   
6. "Electric double layer transistors with ferroelectric BaTiO₃ channels"
   M. Ito, Y. Matsubara, Y. Kozuka, K. S. Takahashi, F. Kagawa, J. T. Ye, Y. Iwasa, K. Ueno, Y. Tokura, M. Kawasaki
   Appl. Phys. Lett. 104 222101 (2014). doi:10.1063/1.4881059
   
7. "Photo-induced sign inversion of the anomalous Hall effect in EuO thin films"
   Y. Ohuchi, Y. Kozuka, N. Rezaei, M. S. Bahramy, R. Arita, K. Ueno, A.Tsukazaki, M. Kawasaki
   Phys. Rev. B 89 121114 (2014) doi:10.1103/PhysRevB.89.121114

   2013

8. "Electric-Field-Induced Superconductivity on an Organic/Oxide Interface"
   K. Ueno,
   Jpn. J. Appl. Phys. 52, 110129-1-8 (2013). doi:10.7567/JJAP.52.110129
9. "ELECTRON CARRIER-MEDIATED ROOM TEMPERATURE FERROMAGNETISM IN ANATASE (Ti,Co)O₂"
   T. Fukumura, Y. Yamada, K. Ueno, H. T. Yuan, H. Shimotani, Y. Iwasa, L. Gu, S. Tsukimoto, Y. Ikuhara, M. Kawasaki
   SPIN 2, 1230005(2013). doi:10.1142/S2010324712300058

   2012

10. "Ultrafast Time-Resolved Faraday Rotation in EuO Thin Films"
    F. Liu, T. Makino, T. Yamasaki, K. Ueno, A. Tsukazaki, T. Fukumura, Y. Kong,M. Kawasaki
    Phys. Rev. Lett. 108 257401-1-5 (2012).
11. Ultrafast optical control of magnetization in EuO thin films
    T. Makino, F. Liu, T. Yamasaki, Y. Kozuka, K. Ueno, A. Tsukazaki, T. Fukumura, Y. Kong, M. Kawasaki
    Phys. Rev. B, 86, 064403-1-4 (2012).
12. "High Crystallinity CuScO₂ Delafossite Films Exhibiting Ultraviolet Photoluminescence Grown by Vapor Liquid Solid Tri-phase Epitaxy"
    Y. Matsubara, T. Makino, H. Hiraga, C. Chen, S. Tsukimoto, K. Ueno, Y. Kozuka, Y. Ikuhara, M. Kawasaki
    Appl. Phys. Express, 5, 011201 (2012).

    2011

13. "Control of ferromagnetism at room temperature in (Ti,Co)O_2-&delta via chemical doping of electron carriers"
    Y. Yamada, T. Fukumura, K. Ueno, M. Kawasaki
    Appl. Phys. Lett. 99, 242502 (2011).
    
14. "Insulating phase of a two-dimensional electron gas in Mg_xZn_1-xO/ZnO heterostructures below nu = (1/3)"
    Y. Kozuka, A. Tsukazaki, D. Maryenko, J. Falson, S. Akasaka, K. Nakahara, S. Nakamura, A. Awaji, K. Ueno, M. Kawasaki
    Phys. Rev. B, 84, 033304 (2011).
    
15. "Electrically-induced ferromagnetism at room temperature in cobalt-doped titanium dioxide"
    Y. Yamada, K. Ueno,T. Fukumura, H. T. Yuan, H. Shimotani, Y. Iwasa, L. Gu, S. Tsukimoto, Y. Ikuhara, M. Kawasaki
    Science 332, 1065 (2011).
    
16. "Discovery of superconductivity in KTaO₃ by electrostatic carrier doping"
    K. Ueno, S. Nakamura, H. Shimotani, H. T. Yuan, N. Kimura, T. Nojima, H. Aoki, Y. Iwasa, M. Kawasaki
    Nature Nanotechnology 6 408 (2011).
    
17. "Observation of anomalous Hall effect in EuO epitaxial thin films grown by a pulse laser deposition"
    T. Yamasaki, K. Ueno, A. Tsukazaki, T. Fukumura, M. Kawasaki
    Appl. Phys. Lett. 98 082116 (2011)
    
18. "Emergence of superconductivity on a SrTiO₃ surface by electric-field charge accumulation"
    K. Ueno, S. Nakamura, H. Shimotani, T. Nojima, Y. Iwasa, M. Kawasaki
    Proc. SPIE 7940 26 (2011)
    

    2010

19. "Electric field control of two-dimensional electrons in polymer-gated oxide semiconductor heterostructures"
    M. Nakano, A. Tsukazaki, A. Ohtomo, K. Ueno, S. Akasaka, H. Yuji, K. Nakahara, T. Fukumura, M. Kawasaki
    Advanced Materials, 22 876 (2010)
    
20. "Epitaxial Structure of (001) and (111)-Oriented Perovskite Ferrate Films Grown by Pulsed-Laser Deposition"
    S. Chakraverty, A. Ohtomo, M. Okude, K. Ueno, M. Kawasaki
    Cryst. Growth Des. 10 1725 (2010)
    
21. "Tuning of the metal-insulator transition in electrolyte-gated NdNiO₃ thin films"
    S. Asanuma, P. H. Xiang, H. Yamada, H. Sato, I. H. Inoue, H. Akoh, A. Sawa, K. Ueno, H. Shimotani, H. Yuan, M. Kawasaki, Y. Iwasa
    Appl. Phys. Lett. 97 142110 (2010).
22. "Electrostatic charge accumulation versus electrochemical doping in SrTiO₃ electric double layer transistors"
    K. Ueno, H. Shimotani, Y. Iwasa, M. Kawasaki
    Appl. Phys. Lett. 96 252107 (2010)
    
23. "Spatial distribution of two-dimensional electron gas in a ZnO/Mg_0.2Zn_0.8O heterostructure probed with a conducting polymer Schottky contact"
    M. Nakano, A. Tsukazaki, K. Ueno, R. Y. Gunji, A. Ohtomo, T. Fukumura, M. Kawasaki
    Appl. Phys. Lett. 96 052116 (2010)
    
24. "High-Throughput Screening of Ultraviolet-Visible Magnetooptical Properties of Spinel Ferrite (Zn,Co)Fe₂O₄ Solid Solution Epitaxial Film by a Composition-Spread Approach"
    Y. Iwasaki, T. Fukumura, H. Kimura, A. Ohkubo, T. Hasegawa, Y. Hirose, T. Makino, K. Ueno, M. Kawasaki
    Appl. Phys. Express 3 103001 (2010)
    

    2009

25. "Co-doped TiO₂ films grown on glass: Room-temperature ferromagnetism accompanied with anomalous Hall effect and magneto-optical effect"
    T. Yamasaki, T. Fukumura, Y. Yamada, M. Nakano, K. Ueno, T. Makino, M. Kawasaki,
    Appl. Phys. Lett.94 102515 (2009).
    

    2008

26. "Electric Field Induced Superconductivity in an Insulator"
    K. Ueno, S. Nakamura, H. Shimotani, A. Ohtomo, N. Kimura, T. Nojima, H. Aoki, Y. Iwasa, M. Kawasaki,
    Nature Materials, 7, 855 (2008).
    
27. "Anomalous Hall effect in anatase Ti_1-xCo_xO_2-δ above room temperature"
    K. Ueno, T. Fukumura, H. Toyosaki, M. Nakano, T. Yamasaki, Y. Yamada, M. Kawasaki,
    J. Appl. Phys. 103, 07D114 (2008).
    (Selected in Virtual Journal of Nanoscale Science & Technology -- February 18, 2008, Volume 17, Issue 7)
    
28. "P-type field-effect transistor of NiO with electric double-layer gating"
    H. Shimotani, H. Suzuki, K. Ueno, M. Kawasaki, and Y. Iwasa,
    Appl. Phys. Lett. 92, 242107 (2008).
    
29. "Transparent polymer Schottky contact for a high performance visible-blind ultraviolet photodiode based on ZnO"
    M. Nakano, T. Makino, A. Tsukazaki, K. Ueno, A. Ohtomo, T. Fukumura, H. Yuji, S. Akasaka, K. Tamura, K. Nakahara, T. Tanabe, A. Kamisawa, M. Kawasaki
    Appl. Phys. Lett. 93, 123309 (2008).
    
30. "Effect of in-situ annealed SnO₂ buffer layer on structural and electrical property of (001) SnO₂/TiO₂ heterostructures, "
    M. Okude, K. Ueno, S. Itoh, M. Kikuchi, A. Ohtomo, M. Kawasaki,
    J. Phys. D : Appl. Phys. 41, 125309 (2008).
    
31. "Role of charge carriers for ferromagnetism in cobalt-doped rutile TiO₂"
    T. Fukumura, H. Toyosaki, K. Ueno, M. Nakano, M. Kawasaki,
    New Journal of Physics 10, 055018 (2008).
    
32. "Quantitative Conductivity Mapping of SrTiO₃-LaAlO₃-LaTiO₃ Ternary Composition-spread Thin Film by Scanning Microwave Microscope"
    S. Okazaki, N. Okazaki, Y. Hirose, J. Nishimura, K. Ueno, A. Ohtomo, M. Kawasaki, H. Koinuma, T. Hasegawa,
    Appl. Phys. Express 1, 055003 (2008).
    
33. "A scaling behavior of anomalous Hall effect in cobalt doped TiO₂"
    T. Fukumura, H. Toyosaki, K. Ueno, M. Nakano, T. Yamasaki, M. Kawasaki
    Frontiers in Materials Research, 10, 87 (2008).
    
34. "Mg_xZn_1-xO-Based Schottky Photodiode for Highly Color-Selective Ultraviolet Light Detection "
    M. Nakano, T. Makino, A. Tsukazaki, K. Ueno, A. Ohtomo, T. Fukumura, H. Yuji, Y. Nishimoto, S. Akasaka, D. Takamizu, K. Nakahara, T. Tanabe, A. Kamisawa, Kawasaki
    Appl. Phys. Express, 1, 121201(2008).
    
35. "Room Temperature Ferromagnetic Semiconductor Rutile Ti_1-xCo_xO_2-δ Epitaxial Thin Films Grown by Sputtering Method"
    T. Yamasaki, T. Fukumura, M. Nakano, K. Ueno, M. Kawasaki
    Appl. Phys. Express 1, 111302 (2008).
    
36. "High throughput Screening for Combinatorial Thin Film Library of Thermoelectric Materials"
    M. Watanabe, T. Kita, T. Fukumura, A. Ohtomo, K. Ueno, M. Kawasaki,
    Journal of Combinatorial Chemistry, 10, 175 (2008).
    
37. "Improved performance of organic light emitting device with anatase TiO₂ anode"
    M. Nakano, T. Fukumura, H. Toyosaki, K. Ueno, M. Kawasaki,
    Japanese Journal of Applied Physics, 47, 1276 (2008).
    

    2007

38. "Anomalous Hall effect in anatase Ti_1-xCo_xO_2-δ at low temperature regime"
    K. Ueno, T. Fukumura, H. Toyosaki, M. Nakano, M. Kawasaki,
    Applied Physics Letters, 90, 72103 (2007).
    
39. "Schottky contact on a ZnO (0001) single crystal with conducting polymer"
    M. Nakano, A. Tsukazaki, R. Y. Gunji, K. Ueno, A. Ohtomo, T. Fukumura, M. Kawasaki,
    Applied Physics Letters 91, 142113 (2007).
    
40. "Combinatorial synthesis and high throughput evaluation of thermoelectric power factor in Mg-Si-Ge ternary compounds"
    M. Watanabe, T. Kita, T. Fukumura, A. Ohtomo, K. Ueno, M. Kawasaki,
    Appl. Surf. Sci. 254, 777 (2007).
    
41. "A scaling relation of anomalous hall effect in ferromagnetic semiconductors and metals"
    T. Fukumura, H. Toyosaki, K. Ueno, M. Nakano, T. Yamasaki, M. Kawasaki,
    Japanese Journal of Applied Physics, 46, L642 (2007).
    

    2006

42. "Field-effect modulation of transport properties of charge-ordered La_1/3Sr_2/3FeO₃ thin films"
    K. Ueno, A. Ohtomo, F. Sato, M. Kawasaki,
    Physical Review B, 73, 165103 (2006).
    
43. "An organic light emitting device employing transparent rutile TiO₂ as an anode"
    M. Nakano, T. Fukumura, H. Toyosaki, K. Ueno, M. Kawasaki,
    Japanese Journal of Applied Physics, 45, L1061 (2006).
    
44. "Ti_1-xCo_xO_2-δ /AlO_x/Fe_0.1Co_0.9 magnetic tunnel junctions with varied AlO_x thickness"
    H. Toyosaki, T. Fukumura, K. Ueno, M. Nakano, M. Kawasaki,
    Journal of Applied Physics, 99, 08M102 (2006).
    
45. "Sr₂TMO₃ (TM = Ni,Co) compounds with 1D TM-O Chains"
    M. Ohtani, H. Kishida, K. Hirota, H. Sakurada, N. Kawamoto, Y. Murakami, K. Ueno, J. Matsuno, Y. Okimoto, T. Makino, Y. Segawa, Y. Tokura, D. Shindo, H. Okamoto, M. Kawasaki,
    Advanced Materials, 18, 2541 (2006).
    

    2005

46. "A ferromagnetic oxide semiconductor as spin injection electrode in magnetic tunnel junction"
    H. Toyosaki, T. Fukumura, K. Ueno, M. Nakano, M. Kawasaki,
    Japanese Journal of Applied Physics, 44, L896 (2005).
    

    2004

47. "Field-effect transistor based on KTaO₃ perovskite"
    K. Ueno, I. H. Inoue, T. Yamada, H. Akoh, Y. Tokura, H. Takagi,
    Applied Physics Letters, 84, 3726 (2004).
    

    2003

48. "Field-Effect Transistor on SrTiO₃ with sputtered Al₂O₃ Gate Insulator"
    K. Ueno, I. H. Inoue, H. Akoh, M. Kawasaki, Y. Tokura, H. Takagi,
    Applied Physics Letters, 83, 1755 (2003).
    

    2000

49. "STM / STS Observation of Co Impurities in Bi_2.1Sr_1.8Ca(Cu_1-xCo_x)₂O_8+y Single Crystals"
    X. Zhao, S. Nakano, K. Ueno, G. Kinoda, T. Endo, T. Hanaguri, K. Kitazawa, T. Hasegawa,
    Physica B, 284-288, 1065 (2000).
    

    1999

50. "Electronic Structures of Two-Phase Microstructures in Pb-doped Bi₂Sr₂CaCu₂O_y"
    S. Nakano, K. Ueno, T. Hasegawa, K. Kitazawa, T. Fujita, Y. Nakayama, T. Motohashi, J. Shimoyama, K. Kishio, T. Hasegawa,
    Journal of Low Temperature Physics, 117, 341 (1999).
    

Last Updated: 2011.4.15