Physics of oxide interfaces

Papers

  1. Q. Shi, J. Falson, M. A. Zudov, Y. Kozuka, A. Tsukazaki, M. Kawasaki, J. Smet
    "Nonlinear response of a MgZnO/ZnO heterostructure close to zero bias"
    Phys. Rev. B 96, 125401-1-4 (2017)
    DOI: 10.1103/PhysRevB.96.125401
  2. D. Maryenko, A. S. Mishchenko, M. S. Bahramy, A. Ernst, J. Falson, Y. Kozuka, A. Tsukazaki, N. Nagaosa, M. Kawasaki
    "Observation of anomalous Hall effect in a non-magnetic two-dimensional electron system"
    Nature Commun. 8, 14777 (2017)
    DOI: 10.1038/ncomms14777
  3. M. Mogi, M. Kawamura, R. Yoshimi, A. Tsukazaki, Y. Kozuka, N. Shirakawa, K. S. Takahashi, M. Kawasaki, Y. Tokura
    "A magnetic heterostructure of topological insulators as a candidate for an axion insulator"
    Nature Mater. 16, 516-521 (2017)
    DOI: 10.1038/nmat4855
  4. Q. Shi, M. A. Zudov, J. Falson, Y. Kozuka, A. Tsukazaki, M. Kawasaki, K. von Klitzing, J. Smet
    "Hall field-induced resistance oscillations in MgZnO/ZnO heterostructures"
    Phys. Rev. B 95, 041411(R)-1-4 (2017)
    DOI: 10.1103/PhysRevB.95.041411
  5. Aswin Vishnuradhan, Y. Kozuka, M. Uchida, J. Falson, A. Tsukazaki, M. Kawasaki
    "Alloy disorder modulated electron transport at MgxZn1-xO/ZnO heterointerface"
    AIP Adv. 7, 15029-1-7 (2017)
    DOI: 10.1063/1.4974462
  6. N. Kanazawa, J. S. White, H. M. Ronnow, C. D. Dewhurst, Y. Fujishiro, A. Tsukazaki, Y. Kozuka, M. Kawasaki, M. Ichikawa, F. Kagawa, and Y. Tokura
    "Direct observation of the anisotropic magnetic field response of the spin helix in FeGe thin film"
    Phys. Rev. B 94, 184432-1-7 (2016)
    DOI: 10.1103/PhysRevB.94.184432
  7. S. Nishihaya, M. Uchida, Y. Kozuka, Y. Iwasa, M. Kawasaki
    "Evolution of insulator-metal phase transitions in epitaxial tungsten oxide films during electrolyte-gating"
    ACS Appl. Mater. Interfaces 8, 22330-22336 (2016)
    DOI: 10.1021/acsami.6b06593
  8. J. Falson, Y. Kozuka, M. Uchida, J. H. Smet, T. Arima, A. Tsukazaki, M. Kawasaki
    "MgZnO/ZnO heterostructures with electron mobility exceeding 1× 106 cm2/Vs"
    Scientific Reports 6, 26598 (2016)
    DOI: 10.1038/srep26598
  9. Y. Matsubara, K. S. Takahashi, M. S. Bahramy, Y. Kozuka, D. Maryenko, J. Falson, A. Tsukazaki, Y. Tokura, M. Kawasaki
    "Observation of the quantum Hall effect in δ-doped SrTiO3"
    Nature Commun. 7, 11631 (2016)
    DOI: 10.1038/ncomms11631
  10. T. C. Fujita, M. Uchida, Y. Kozuka, W. Sano, A. Tsukazaki, T. Arima, M. Kawasaki
    "All-in-all-out magnetic domain wall conduction in pyrochlore iridate heterointerface"
    Phys. Rev. B 93, 064419-1-6 (2016)
    DOI: 10.1103/PhysRevB.93.064419
  11. M. Uchida, K. Ohba, Y. Ohuchi, Y. Kozuka, M. Kawasaki
    "Epitaxially stabilized oxide composed of twisted triangular-lattice layers"
    Chem. Mater. 28, 1165-1169 (2016)
    DOI: 10.1021/acs.chemmater.5b04702
  12. M. Ito, M. Uchida, Y. Kozuka, K. S. Takahashi, M. Kawasaki
    "Effective carrier doping and metallization in LaxSr2−xyBayIrO4−δ thin films"
    Phys. Rev. B 93, 045139-1-5 (2016)
    DOI: 10.1103/PhysRevB.93.045139
  13. T. C. Fujita, M. Uchida, Y. Kozuka, S. Ogawa, A. Tsukazaki, T. Arima, M. Kawasaki
    "All-in-all-out magnetic domain size in pyrochlore iridate thin films as probed by local magnetotransport"
    Appl. Phys. Lett. 108, 022402-1-5 (2016)
    DOI: 10.1063/1.4939742
  14. D. F. Kärcher, A. V. Shchepetilnikov, Yu. A. Nefyodov, J. Falson, I. A. Dmitriev, Y. Kozuka, D. Maryenko, A. Tsukazaki, S. I. Dorozhkin, I. V. Kukushkin, M. Kawasaki, J. H. Smet
    "Observation of microwave induced resistance oscillations in MgZnO/ZnO heterostructures"
    Phys. Rev. B 93, 041410(R)-1-5 (2016)
    DOI: 10.1103/PhysRevB.93.041410
  15. S. Seki, T. Ideue, M. Kubota, Y. Kozuka, R. Takagi, M. Nakamura, Y. Kaneko, M. Kawasaki, Y. Tokura
    "Thermal generation of spin current in an antiferromagnet"
    Phys. Rev. Lett. 115, 266601-1-5 (2015)
    DOI: 10.1103/PhysRevLett.115.266601
  16. T. Murata, Y. Kozuka, M. Uchida, M. Kawasaki
    "Magnetic properties of spin frustrated spinel ZnFe2O4/ZnCr2O4 superlattices"
    J. Appl. Phys. 118, 193901-1-5 (2015)
    DOI: 10.1063/1.4935818
    Highlighted in MRS Bulletin and in a review article of MRS communications
  17. M. Mogi, R. Yoshimi, A. Tsukazaki, K. Yasuda, Y. Kozuka, K. S. Takahashi, M. Kawasaki, Y. Tokura
    "Magnetic modulation doping in topological insulators toward higher-temperature quantum anomalous Hall effect"
    Appl. Phys. Lett. 107, 182401-1-5 (2015)
    DOI: 10.1063/1.4935075
  18. D. Maryenko, J. Falson, M. S. Bahramy, I. A. Dmitriev, Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Spin-selective electron quantum transport in non-magnetic MgZnO/ZnO-heterostructures"
    Phys. Rev. Lett. 115, 197601-1-5 (2015)
    DOI: 10.1103/PhysRevLett.115.197601
  19. T. Yokouchi, N. Kanazawa, A. Tsukazaki, Y. Kozuka, A. Kikkawa, Y. Taguchi, M. Kawasaki, M. Ichikawa, F. Kagawa, Y. Tokura
    "Formation of in-plane skyrmions in epitaxial MnSi thin films as revealed by planar Hall effect"
    J. Phys. Soc. Jpn. 84, 104708-1-5 (2015)
    DOI: 10.7566/JPSJ.84.104708
  20. J. Falson, Y. Kozuka, J. H. Smet, T. Arima, A. Tsukazaki, M. Kawasaki
    "Electron scattering times in ZnO based polar heterostructures"
    Appl. Phys. Lett. 107, 082102-1-4 (2015)
    DOI: 10.1063/1.4929381
  21. M. Uchida, W. Sano, K. S. Takahashi, T. Koretsune, Y. Kozuka, R. Arita, Y. Tokura, M. Kawasaki
    "Field-direction control of the type of charge carriers in nonsymmorphic IrO2"
    Phys. Rev. B 91, 241119(R)-1-5 (2015)
    DOI: 10.1103/PhysRevB.91.241119
  22. E. Majima, Y. Kozuka, M. Uchida, M. Nakamura, M. Kawasaki
    "Band alignment and photovoltaic effect of epitaxial α-PbO thin films"
    Appl. Phys. Express 8, 074001-1-4 (2015)
    DOI: 10.7567/APEX.8.074001
  23. Y. Ohuchi, Y. Kozuka, M. Uchida, K. Ueno, A. Tsukazaki, M. Kawasaki
    "Topological Hall effect in thin films of the Heisenberg ferromagnet EuO"
    Phys. Rev. B 91, 245115-1-5 (2015)
    DOI: 10.1103/PhysRevB.91.245115
  24. T. C. Fujita, Y. Kozuka, M. Uchida, A. Tsukazaki, T. Arima, M. Kawasaki
    "Odd-parity magnetoresistance in pyrochlore iridate thin films with broken time-reversal symmetry"
    Scientific Reports 5, 9711 (2015)
    DOI: 10.1038/srep09711
  25. R. Yoshimi, A. Tsukazaki, Y. Kozuka, J. Falson, K. S. Takahashi, J. G. Checkelsky, N. Nagaosa, M. Kawasaki, Y. Tokura
    "Quantum Hall effect on top and bottom surface states of topological insulator (Bi1-xSbx)2Te2 films"
    Nature Commun. 6, 6627 (2015)
    DOI: 10.1038/ncomms7627
  26. J. Falson, D. Maryenko, B. Friess, D. Zhang, Y. Kozuka, A. Tsukazaki, J. H. Smet, M. Kawasaki
    "Even-denominator fractional quantum Hall physics in ZnO"
    Nature Phys. 11, 347-351 (2015)
    DOI: 10.1038/nphys3259
  27. V. V. Solovyev, A. B. Van'kov, I. V. Kukushkin, J. Falson, D. Zhang, D. Maryenko, Y. Kozuka, A. Tsukazaki, J. H. Smet, M. Kawasaki
    "Optical probing of MgZnO/ZnO heterointerface confinement potential energy levels"
    Appl. Phys. Lett. 106, 082102-1-4 (2015)
    DOI: 10.1063/1.4913313
  28. V. E. Kozlov, A. B. Van'kov, S. I. Gubarev, I. V. Kukushkin, V. V. Solovyev, J. Falson, D. Maryenko, Y. Kozuka, A. Tsukazaki, M. Kawasaki, J. H. Smet
    "Microwave magnetoplasma resonances of two-dimensional electrons in MgZnO/ZnO heterojunctions"
    Phys. Rev. B 91, 085304-1-6 (2015)
    DOI: 10.1103/PhysRevB.91.085304
  29. N. Kanazawa, M. Kubota, A. Tsukazaki, Y. Kozuka, K. S. Takahashi, M. Kawasaki, M. Ichikawa, F. Kagawa, Y. Tokura
    "Discretized topological Hall effect emerging from skyrmions in constricted geometry"
    Phys. Rev. B 91, 041122(R)-1-5 (2015)
    DOI: 10.1103/PhysRevB.91.041122
  30. M. Uchida, J. Falson, Y. Segawa, Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Calibration and control of in-plane Mg doping distribution in MgxZn1-xO/ZnO heterostructures grown by molecular beam epitaxy"
    Jpn. J. Appl. Phys. 54, 028004-1-3 (2015)
    DOI: 10.7567/JJAP.54.028004
  31. D. Maryenko, J. Falson, Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Polarization-dependent Landau level crossing in a two-dimensional electron system in a MgZnO/ZnO heterostructure"
    Phys. Rev. B 90, 245303-1-5 (2014)
    DOI: 10.1103/PhysRevB.90.245303
  32. T. Tambo, J. Falson, D. Maryenko, Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Air-gap gating of MgZnO/ZnO heterostructures"
    J. Appl. Phys. 116, 084310-1-5 (2014)
    DOI: 10.1063/1.4894155
  33. J. G. Checkelsky, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, Y. Kozuka, J. Falson, M. Kawasaki, Y. Tokura
    "Trajectory of anomalous Hall effect toward the quantized state in a ferromagnetic topological insulator"
    Nature Phys. 10, 731-736 (2014)
    DOI: 10.1038/nphys3053
  34. K. Imasaka, J. Falson, Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Spontaneous polarization driven Mg concentration profile reconstruction in MgZnO/ZnO heterostructures"
    Appl. Phys. Lett. 104, 242112-1-5 (2014)
    DOI: 10.1063/1.4884383
  35. M. Ito, Y. Matsubara, Y. Kozuka, K. S. Takahashi, F. Kagawa, J. T. Ye, Y. Iwasa, K. Ueno, Y. Tokura, M. Kawasaki
    "Electric double layer transistor with ferroelectric BaTiO3 channels"
    Appl. Phys. Lett. 104, 222101-1-4 (2014)
    DOI: 10.1063/1.4881059
  36. Y. Ohuchi, Y. Kozuka, N. Rezaei, M. S. Bahramy, R. Arita, K. Ueno, A. Tsukazaki, M. Kawasaki
    "Photo-induced sign inversion of the anomalous Hall effect in EuO thin films"
    Phys. Rev. B 89, 121114(R)-1-5 (2014)
    DOI: 10.1103/PhysRevB.89.121114
  37. M. Brasse, S. M. Sauther, J. Falson, Y. Kozuka, A. Tsukazaki, Ch. Heyn, M. A. Wilde, M. Kawasaki, D. Grundler
    "Enhanced quantum oscillatory magnetization and non-equilibrium currents in an interacting two-dimensional electron system in MgZnO/ZnO with repulsive scatterers"
    Phys. Rev. B 89, 075307-1-5 (2014)
    DOI: 10.1103/PhysRevB.89.075307
  38. T. Yokouchi, N. Kanazawa, A. Tsukazaki, Y. Kozuka, M. Kawasaki, M. Ichikawa, F. Kagawa, Y. Tokura
    "Stability of two-dimensional skyrmions in thin films of Mn1-xFexSi as investigated by topological Hall effect"
    Phys. Rev. B 89, 064416-1-6 (2014)
    DOI: 10.1103/PhysRevB.89.064416
  39. Y. Kozuka, A. Tsukazaki, M. Kawasaki
    "Challenges and opportunities of ZnO-related single crystalline heterostructures"
    Appl. Phys. Rev. 1, 011303-1-18 (2014)
    DOI: 10.1063/1.4853535
  40. V. E. Kozlov, A. B. Van'kov, S. I. Gubarev, I. V. Kukushkin, J. Falson, D. Maryenko, Y. Kozuka, A. Tsukazaki, M. Kawasaki, J. H. Smet
    "Observation of plasma and magnetoplasma resonances of two-dimensional electrons in a single MgZnO/ZnO heterojunction"
    JETP Lett. 98, 223-226 (2013)
    DOI: 10.1134/S0021364013170074
  41. Y. Kozuka, S. Teraoka, J. Falson, A. Oiwa, A. Tsukazaki, S. Tarucha, M. Kawasaki
    "Rashba spin-orbit interaction in a MgxZn1-xO/ZnO two-dimensional electron gas studied by electrically detected electron spin resonance"
    Phys. Rev. B 87, 205411-1-5 (2013)
    DOI: 10.1103/PhysRevB.87.205411
  42. T. C. Fujita, Y. Kozuka, H. Seki, M. Kawasaki
    "Charge-spin-coupled electrical transport properties in EuMoO3/SrTiO3 superlattices"
    Phys. Rev. B 87, 205402-1-8 (2013)
    DOI: 10.1103/PhysRevB.87.205402
  43. Y. Kasahara, Y. Oshima, J. Falson, Y. Kozuka, A. Tsukazaki, M. Kawasaki, Y. Iwasa
    "Correlation-enhanced effective mass of two-dimensional electrons in MgxZn1-xO/ZnO heterostructures"
    Phys. Rev. Lett. 109, 246401-1-5 (2012)
    DOI: 10.1103/PhysRevLett.109.246401
  44. Y. Kozuka, H. Seki, T. C. Fujita, S. Chakraverty, K. Yoshimatsu, H. Kumigashira, M. Oshima, M. S. Bahramy, R. Arita, M. Kawasaki
    "Epitaxially stabilized EuMoO3: A new itinerant ferromagnet"
    Chem. Mater. 24, 3746-3750 (2012)
    DOI: 10.1021/cm302231k
  45. Y. Kozuka, J. Falson, Y. Segawa, T. Makino, A. Tsukazaki, M. Kawasaki
    "Precise calibration of Mg concentration in MgxZn1-xO thin films grown on ZnO substrates"
    J. Appl. Phys. 112, 043515-1-5 (2012)
    DOI: 10.1063/1.4748306
  46. M. Kim, Y. Kozuka, C. Bell, Y. Hikita, H. Y. Hwang
    "Intrinsic spin-orbit coupling in superconducting δ-doped SrTiO3 heterostructures"
    Phys. Rev. B 86, 085121-1-6 (2012)
    DOI: 10.1103/PhysRevB.86.085121
  47. T. Makino, F. Liu, T. Yamasaki, Y. Kozuka, K. Ueno, A. Tsukazaki, T. Fukumura, Y. Kong, M. Kawasaki
    "Ultrafast optical control of magnetization in EuO thin films"
    Phys. Rev. B 86, 064403-1-5 (2012)
    DOI: 10.1103/PhysRevB.86.064403
  48. D. Maryenko, J. Falson, Y. Kozuka, A. Tsukazaki, M. Onoda, H. Aoki, M. Kawasaki
    "Temperature dependent magnetotransport around ν = 1/2 in ZnO heterostructures"
    Phys. Rev. Lett. 108, 186803-1-5 (2012)
    DOI: 10.1103/PhysRevLett.108.186803
  49. Y. Kozuka, A. Tsukazaki, D. Maryenko, J. Falson, C. Bell, M. Kim, Y. Hikita, H. Y. Hwang, M. Kawasaki
    "Single-valley quantum Hall ferromagnet in a dilute MgxZn1-xO/ZnO strongly correlated two-dimensional electron system"
    Phys. Rev. B 85, 075302-1-5 (2012)
    DOI: 10.1103/PhysRevB.85.075302
  50. Y. Matsubara, T. Makino, H. Hiraga, C. Chen, S. Tsukimoto, K. Ueno, Y. Kozuka, Y. Ikuhara, M. Kawasaki
    "High crystallinity CuScO2 delafossite films exhibiting ultraviolet photoluminescence grown by vapor-liquid-solid tri-phase epitexy"
    Appl. Phys. Express 5, 011201-1-3 (2012)
    DOI: 10.1143/APEX.5.011201
  51. S. Chakraverty, K. Yoshimatsu, Y. Kozuka, H. Kumigashira, M. Oshima, T. Makino, A. Ohtomo, M. Kawasaki
    "Magnetic and electronic properties of ordered double-perovskite La2VMnO6 thin films"
    Phys. Rev. B 84, 132411-1-4 (2011)
    DOI: 10.1103/PhysRevB.84.132411
  52. M. Kim, C. Bell, Y. Kozuka, M. Kurita, Y. Hikita, H. Y. Hwang
    "Fermi surface and superconductivity in low-density high-mobility δ-doped SrTiO3"
    Phys. Rev. Lett. 107, 106801-1-4 (2011)
    DOI: 10.1103/PhysRevLett.107.106801
  53. J. Falson, D. Maryenko, Y. Kozuka, A. Tsukazai, M. Kawasaki
    "Magnesium doping controlled density and mobility of two-dimensional electron gas in MgxZn1-xO/ZnO heterostructures"
    Appl. Phys. Express 4, 091101-1-3 (2011)
    DOI: 10.1143/APEX.4.091101
  54. Y. Ishida, H. Kanto, A. Kikkawa, Y. Taguchi, Y. Ito, Y. Ota, K. Okazaki, W. Malaeb, M. Mulazzi, M. Okawa, S. Watanabe, C.-T. Chen, M. Kim, C. Bell, Y. Kozuka, H. Y. Hwang, Y. Tokura, S. Shin
    "Common origin of the circular-dichroism pattern in ARPES of SrTiO3 and CuxBi2Se3"
    Phys. Rev. Lett. 107, 077601-1-4 (2011)
    DOI: 10.1103/PhysRevLett.107.077601
  55. Y. Kozuka, A. Tsukazaki, D. Maryenko, J. Falson, S. Akasaka, K. Nakahara, S. Nakamura, S. Awaji, K. Ueno, M. Kawasaki
    "Insulating phase of a two-dimensional electron gas in MgxZn1-xO/ZnO heterostructures below ν = 1/3"
    Phys. Rev. B 84, 033304-1-4 (2011)
    DOI: 10.1103/PhysRevB.84.033304
  56. Y. Kozuka, M. Kim, H. Ohta, Y. Hikita, C. Bell, H. Y. Hwang
    "Enhancing the electron mobility via delta-doping in SrTiO3"
    Appl. Phys. Lett. 94, 222115-1-3 (2010)
    DOI: 10.1063/1.3524198
  57. Y. Kozuka, Y. Hikita, C. Bell, H. Y. Hwang
    "Dramatic mobility enhancements in doped SrTiO3 thin films by defect management"
    Appl. Phys. Lett. 94, 012107-1-3 (2010)
    DOI: 10.1063/1.3457994
  58. Y. Kozuka, M. Kim, C. Bell, B. G. Kim, Y. Hikita, H. Y. Hwang
    "Two-dimensional normal-state quantum oscillations in a superconducting heterostructure"
    Nature 462, 487-490 (2009)
    DOI: 10.1038/nature08566
  59. C. Bell, S. Harashima, Y. Kozuka, M. Kim, B. G. Kim, Y. Hikita, H. Y. Hwang
    "Dominant mobility modulation by the electronic field effect at the LaAlO3/SrTiO3 interface"
    Phys. Rev. Lett. 103, 226802-1-4 (2009)
    DOI: 10.1103/PhysRevLett.103.226802
  60. Y. Kozuka, T. Susaki, H. Y. Hwang
    "Vanishing Hall coefficient in the extreme quantum limit in photocarrier-doped SrTiO3"
    Phys. Rev. Lett. 101, 096601-1-4 (2008)
    DOI: 10.1103/PhysRevLett.101.096601
  61. T. Susaki, Y. Kozuka, Y. Tateyama, H. Y. Hwang
    "Temperature-dependent polarity reversal in Au/Nb:SrTiO3 Schottky junctions"
    Phys. Rev. B 76, 155110-1-4 (2007)
    DOI: 10.1103/PhysRevB.76.155110
  62. Y. Kozuka, Y. Hikita, T. Susaki, H. Y. Hwang
    "Optically tuned dimensionality crossover in photocarrier-doped SrTiO3: Onset of weak localization"
    Phys. Rev. B 76, 085129-1-6 (2007)
    DOI: 10.1103/PhysRevB.76.085129
  63. Y. Hikita, Y. Kozuka, T. Susaki, H. Takagi, H. Y. Hwang
    "Characterization of the Schottky barrier in SrRuO3/Nb:SrTiO3 junctions"
    Appl. Phys. Lett. 90, 143507-1-3 (2007)
    DOI: 10.1063/1.2719157
  64. Y. Kozuka, T. Susaki, H. Y. Hwang
    "Rectifying NdNiO3/Nb:SrTiO3 junctions as a probe of the surface electronic structure of NdNiO3"
    Appl. Phys. Lett. 88, 142111-1-3 (2006)
    DOI: 10.1063/1.2193800

Reviews

  1. Joseph Falson, Yusuke Kozuka, Atsushi Tsukazaki, Masashi Kawasaki
    "Two-dimensional quantum transport in high-quality ZnO heterointerfaces"
    OYO BUTURI 84, 984-990 (2015)
    [in Japanese]
  2. Atsushi Tsukazaki, Yusuke Kozuka, Masashi Kawasaki
    "Recent development in ZnO related heterostructures towards optical and electrical applications"
    The Journal of the Institute of Electronics, Information and Communication Engineers 97, 227-232 (2014)
    [in Japanese]