Dr. Kensuke KOBAYASHI       (Japanese/English)            last update Mar. 2004

Address

Institute for Solid State Physics (ISSP), University of Tokyo

Kashiwanoha, Kashiwa-shi, Chiba 277-8581, Japan

Tel/Fax: +81-471-36-3301

E-mail: knsk@issp.u-tokyo.ac.jp

 

Date of Birth May 28, 1971        Nationality Japan

Education

University of Tokyo, Doctor course, Physics (Apr. 1996 - Apr. 1998)

Advisor: Prof. A. Fujimori

Doctor Thesis: Spectroscopic Studies of Metal Oxides with Competing Electron-Electron and Electron-Lattice Interactions (Sep. 1999)

University of Tokyo, M. S., Physics (Apr. 1994 - Mar. 1996)

Advisor: Prof. A. Fujimori

Thesis: Photoemission study of intermetallic superconductors: Boro-carbides and Chevrel-phase compounds

University of Tokyo, B. S. Physics (Apr. 1990 - Mar. 1994)

Work Experience

Research Associate, Institute for Solid State Physics (ISSP), University of Tokyo (Aug. 1999 - present)

Research Associate, Department of Physics, University of Tokyo (Apr. 1998 - Aug. 1999)

Fellowships Awarded for Research

Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists (Apr. 1996 - Apr. 1998)

Research Work

Aug. 1999 - present

·         Mesoscopic physics: quantum dot, Aharonov-Bohm ring, and coherence of electrons.

·         Nano-fabrication techniques: electron lithography, photolithography, etc.

·         Measurement techniques: precise measurements at low temperatures down to mK.

·         Molecular beam epitaxy (MBE): growth of two-dimensional electron/hole gas systems, quantum well systems etc.

Apr. 1994 - Aug. 1999

·         Photoemission spectroscopy of highly correlated systems and superconductors (boro-carbides, Chevrel-phase compounds, BKBO, NaV2O5, Ti4O7, high-Tc compounds, manganites, etc.).

·           Spectroscopic techniques: ultra-violet photoemission spectroscopy (UPS), UPS with high-energy resolution, x-ray photoemission spectroscopy (XPS), Bremsstrahlung isochromat spectroscopy (BIS), angle-resolved photoemission spectroscopy (ARPES), and x-ray absorption spectroscopy (XAS).

·           Development of high-resolution UPS systems for low temperature measurements.

·           Band-structure calculations.

 

KEY PUBLICATIONS

1.        H. Aikawa, K. Kobayashi, A. Sano, S. Katsumoto, and Y. Iye: Observation of "Partial Coherence" in an Aharonov-Bohm Interferometer with a Quantum Dot, Phys. Rev. Lett. (accepted); cond-mat/0309084.

2.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Probe-Configuration-Dependent Decoherence in an Aharonov-Bohm Ring, Journal of the Physical Society of Japan 71, L2094-2097 (2002); cond-mat/0204186.

3.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Tuning of the Fano Effect through a Quantum Dot in an Aharonov-Bohm Interferometer, Phys. Rev. Lett. 88, 256806-256809 (2002); cond-mat/0202006, Mesoscopic Fano effect in a quantum dot embedded in an Aharonov-Bohm ring, Phys. Rev. B 68, 235304 (2003); cond-mat/0309570.

4.        K. Kobayashi, T. Susaki, A. Fujimori, T. Tonogai, and H. Takagi: Disorder Effects in the Bipolaron System Ti4O7 Studied by Photoemission Spectroscopy, Europhys. Lett. 59, 868-874 (2002); cond-mat/9909189.

5.        K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, Y. Ueda, T. Tohyama, and S. Maekawa: Finite Temperature Effects in One-dimensional Mott-Hubbard Insulator: Angle-Resolved Photoemission Study of Na0.96V2O5, Phys. Rev. Lett. 82, 803-806 (1999); cond-mat/9808334.

6.        K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, and Y. Ueda: Single-Particle Excitations in One-Dimensional Mott-Hubbard Insulator NaV2O5, Phys. Rev. Lett. 80, 3121-3124 (1998).

 

INVITED TALKS & SEMINARS

1.        K. Kobayashi: Phase and Coherence of Electrons in Low-dimensional Nanostructures (Prof. H. Ebisawa, Tohoku University, Sendai, Japan, November 2001).

2.        K. Kobayashi: Phase Controlling and Coherence in an Aharonov-Bohm Ring, 14-th Sasaki SymposiumiRIKEN, Wako, Japan, November 2001j.

3.        K. Kobayashi: Phase and Coherence of Electrons through a Quantum Dot and an Aharonov-Bohm Ring (Prof. K. Ueda, ISSP, Univ. of Tokyo, Kashiwa, Japan, April 2002).

4.         K. Kobayashi: Phase and Coherence of Electrons through a Quantum Dot and an Aharonov-Bohm Ring (Prof. Markus Büttiker, Département de Physique Théorique Université de Genève, Genève, Switzerland, July 2002).

5.        K. Kobayashi: Phase and Coherence of Electrons through a Quantum Dot and an Aharonov-Bohm Ring (Prof. Klaus Ensslin, Solid State Physics Laboratory, ETH Zurich, Switzerland, July 2002).

6.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Tunable Fano System: a Quantum Dot Embedded in an Aharonov-Bohm Ring, The 23rd International Conference on Low Temperature Physics (LT23) (Hiroshima, Japan, August 2002).

7.        K. Kobayashi: Phase and coherence of electrons through a quantum dot and an Aharonov-Bohm ring, International Seminar on Electrons in zero-dimensional conductors: Beyond the single-particle picture (ZEDICO), (Max-Planck-Institut für Physik komplexer Systeme, Dresden, Germany, November 2002).

8.        K. Kobayashi: Mesoscopic Fano Effect in a Quantum-Dot-Aharonov-Bohm-Ring Hybrid System (Profs. Saso and Kontani, Saitama University, Saitama, Japan, March 2003).

9.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Mesoscopic Fano Effect through a Quantum Dot in an Aharonov-Bohm Ring, The 15th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-15) (Nara, Japan, July 2003).

10.     K. Kobayashi: Phase and coherence of electrons through a quantum hybrid system (Prof. Yuval Gefen, The Weizmann Institute of Science, Israel, January 2004).

11.     K. Kobayashi: Phase and coherence of electrons through a quantum hybrid system (Prof. Baruch Horovitz, Ben-Gurion University, Israel, January 2004).

12.     K. Kobayashi: Phase and coherence of electrons through a quantum hybrid system (Prof. Amnon Aharohy, Tel Aviv University, Israel, January 2004).

 

INTERNATIONAL CONFERENCES (Contributed)

1.        K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, and Y. Ueda: Angle Resolved Photoemission Study of the Spin-Peierls System a'-NaV2O5, TODAI Symposium 1997 and the 6th ISSP International Symposium (ISSP-6) on Frontiers in Synchrotron Radiation Spectroscopy (Tokyo, Japan, October 1997).

2.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Observation-dependent Dephasing in an Aharonov-Bohm Ring, The 7th International Symposium on Foundations of Quantum Mechanics In the Light of New Technology (ISQM-Tokyo f01) (Tokyo, Japan, August 2001).

3.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Observation of an Enhanced Aharonov-Bohm Effect, TODAI Symposium ISSP-Kashiwa 2001 (Kashiwa, October 2001) (invited poster).

4.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Reduction of Quantum Decoherence in Non-Local Resistance Measurement, Fifth International Symposium on New Phenomena in Mesoscopic Structures (NPMS-5) (Waikoloa, Hawaii, USA, November 2001) (oral).

5.        H. Aikawa, K. Kobayashi, S. Katsumoto, and Y. Iye: Suppression of Quantum Decoherence in an Aharonov-Bohm Ring (Localization 2002) (Tokyo, Japan, June 2002) (oral).

6.        K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: A Tunable Fano System Realized in a Quantum Dot in an Aharonov-Bohm Ring, 26th International Conference on the Physics of Semiconductors (ICPS-26) (Edinburgh, the United Kingdom, July 2002) (oral).

7.        H. Aikawa, K. Kobayashi, S. Katsumoto, and Y. Iye: Suppression of Quantum Decoherence in Nonlocal Resistance Measurement (ICPS-26) (Edinburgh, the United Kingdom, July 2002).

8.        H. Aikawa, K. Kobayashi, A. Sano, S. Katsumoto, and Y. Iye: Spin-flip Process and Quantum Decoherence in a Quantum Dot, the 15th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-15) (Nara, Japan, July 2003).

 

LIST OF PUBLICATIONS

1.        A. Fujimori, K. Kobayashi, T. Mizokawa, K. Mamiya, A. Sekiyama, H. Eisaki, H. Takagi, S. Uchida, R.J. Cava, J. J. Krajewski, and W. F. Peck, Jr.: Photoemission and Inverse-Photoemission Study of Superconducting YNi2B2C: Effects of Electron-Electron and Electron-Phonon Interactions, Phys. Rev. B 50, R9660-9663 (1994).

2.        A. Fujimori, K. Kobayashi, T. Mizokawa, K. Mamiya, A. Sekiyama, H. Eisaki, H. Takagi, S. Uchida, R. J. Cava, J. J. Krajewski, and W. F. Peck, Jr.: Spectral Weight Transfer and Mass Renormalization in LnNi2B2C (Ln = Y and La), J. Phys. Chem. Solids. 56, 1875-1876 (1995).

3.        K. Morikawa, T. Mizokawa, K. Kobayashi, A. Fujimori, H. Eisaki, S. Uchida, F. Iga, and Y. Nishihara: Spectral Weight Transfer and Mass Renormalization in Mott-Hubbard Systems SrVO3 and CaVO3: Influence of Long-Range Coulomb Interaction, Phys. Rev. B 52, 13711-13714 (1995).

4.        S.Shin, A. Agui, M. Watanabe, M. Fujisawa, Y. Tezuka, T. Ishii, K. Kobayashi, A. Fujimori, M. Hinomaru, and H. Takagi: Soft X-Ray Emission Studies of YNi2B2C andLaNi2B2C: Observation of the B2p and C2p Partial Density of States, Phys. Rev. B 52, 15082-15085 (1995).

5.        A. Fujimori, A. E. Bocquet, K. Morikawa, K. Kobayashi, T. Saitoh, Y. Tokura, I. Hase, and M. Onoda: Electronic Structure and Electron-Phonon Interaction in Transition-Metal Oxides with d0 Configuration and Lightly Doped Compounds, J. Phys. Chem. Solids 57, 1379-1384 (1996).

6.        D. D. Sarma, N. Shanthi, S. R. Krishnakumar, T. Saitoh, T. Mizokawa, A. Sekiyama, K. Kobayashi, A. Fujimori, E. Weschke, R. Meier, G. Kaindl, Y. Takeda, and M. Takano: Temperature-Dependent Photoemission Spectral Weight in La0.6Sr0.4MnO3, Phys. Rev. B 53, 6873-6876 (1996).

7.         K. Kobayashi, T. Mizokawa, K. Mamiya, A. Sekiyama, A. Fujimori, H. Takagi, H. Eisaki, S. Uchida, R. J. Cava, J. J. Krajewski, and W. F. Peck, Jr.: Photoemission Study of Ni-Boro-Carbides: Superconducting YNi2B2C and Non-Superconducting LaNi2B2C, Phys. Rev. B 54, 507-514 (1996).

8.         T. Susaki, A. Sekiyama, K. Kobayashi, T. Mizokawa, A. Fujimori, M. Tsunekawa, T. Muro, T. Matsushita, S. Suga, H. Ishii, T. Hanyu, A. Kimura, H. Namatame, M. Taniguchi, T. Miyahara, F. Iga, M. Kasaya, and H. Harima: Low-Energy Electronic Structure of the Kondo Insulator YbB12, Phys. Rev. Lett. 77, 4269-4272 (1996).

9.        T. Saitoh, A. Sekiyama, K. Kobayashi, T. Mizokawa, A. Fujimori, D. D. Sarma, Y. Takeda, and M. Takano: Temperature-Dependent Valence-Band Photoemission Spectra of La1-xSrxMnO3, Phys. Rev. B 56, 8836-8840 (1997).

10.     T. Susaki, A. Sekiyama, K. Kobayashi, T. Mizokawa, A. Fujimori, M. Tsunekawa, T. Muro, T. Matsushita, S. Suga, H. Ishii, T. Hanyu, A. Kimura, H. Namatame, M. Taniguchi, T. Miyahara, F. Iga, M. Kasaya, and H. Harima: Susaki et al. Reply (Reply to Comment hIntrinsic Photoemission Spectra for YbB12h), Phys. Rev. Lett. 78, 1832 (1997).

11.     K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, and Y. Ueda: Single-Particle Excitations in One-Dimensional Mott-Hubbard Insulator NaV2O5, Phys. Rev. Lett. 80, 3121-3124 (1998).

12.     K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, and Y. Ueda: Angle Resolved Photoemission Study of the Spin-Peierls System a'-NaV2O5, J. Electron Spectrosc. Relat. Phenom., 92, 87-90 (1998).

13.     T.Konishi, K. Mamiya, K. Morikawa, K. Kobayashi, T. Mizokawa, A. Fujimori, F. Iga, H. Kawanaka, Y. Nishihara, A. Delin, and O. Eriksson: Photoemission and inverse-photoemission study of ferromagnetic valence fluctuating system CeFe2, J. Electron Spectrosc. Relat. Phenom. 88-91, 303-307 (1998).

14.     T. Konishi, K. Kobayashi, K. Mamiya, T. Mizokawa, S. Nohara, A. Fujimori, and T. Takabatake: Photoemission and inverse-photoemission study of CeNiSn, J. Electron Spectrosc. Relat. Phenom. 88-91, 411-414 (1998).

15.     A. Ino, T. Mizokawa, K. Kobayashi, A. Fujimori, T. Sasagawa, T. Kimura, K. Kishio, K. Tamasaku, H. Eisaki, and S. Uchida: Doping Dependent Density of States and Pseudogap behavior in La2-xSrxCuO4, Phys. Rev. Lett. 81, 2124-2127 (1998), cond-mat/9806341.

16.     K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe, Y. Ueda, T. Tohyama, and S. Maekawa: Finite Temperature Effects in One-dimensional Mott-Hubbard Insulator: Angle-Resolved Photoemission Study of Na0.96V2O5, Phys. Rev. Lett. 82, 803-806 (1999), cond-mat/9808334.

17.     K. Kobayashi, T. Mizokawa, A. Ino, J. Matsuno, A. Fujimori, H. Samata, A. Mishiro, Y. Nagata, and F. M. F. de Groot: Doping Dependence of the Electronic Structure of Ba1-xKxBiO3 Studied by X-Ray Absorption Spectroscopy, Phys. Rev. B 59, 15100-15106 (1999), cond-mat/9903261.

18.     J. Matsuno, K. Kobayashi, A. Fujimori, L. F. Mattheiss, and Y. Ueda: Electronic struc-ture of the gheavy-fermionh systems LiV2O4, Physica B 281, 28-29 (2000).

19.     M. Satake, K. Kobayashi, T. Mizokawa, A. Fujimori, T. Tanabe, T. Katsufuji, and Y.Tokura: Charge ordering and chemical potential shift in La2-xSrxNiO4studied by photoemission spectroscopy, Phys. Rev. B 61, 15515-15518 (2000), cond-mat/9908014.

20.     T. Konishi, K. Morikawa, K. Kobayashi, T. Mizokawa, A. Fujimori, K. Mamiya, F. Iga, H. Kawanaka, Y. Nishihara, A. Delin, and O. Eriksson: Electronic structure of the strongly hybridized ferromagnet CeFe2, Phys. Rev. B 62, 14304-14312 (2000), cond-mat/0009200.

21.     A. Fujimori, T. Yoshida, K. Okazaki, T. Tsujioka, K. Kobayashi, T. Mizokawa, M. Onoda, T. Katsufuji, Y. Taguchi, and Y. Tokura: Electronic structure of Mott-Hubbard-type transition-metal oxides, J. Electron Spectrosc. Relat. Phenom., 117, 277-286 (2001).

22.     K. Kobayashi, A. Fujimori, T. Ohtani, I. Dasgupta, O. Jepsen, and O. K. Andersen: Electronic structure of the Chevrel-phase compounds SnxMo6Se7.5: Photoemission spectroscopy and band-structure calculations, Phys. Rev. B 63, 195109-195115 (2001); cond-mat/0011231.

23.     T. Susaki, K. Kobayashi, A. Fujimori A. Ohno, T. Tonogai, and H. Takagi: Effects of hole doping in FeSi: Photoemission study of FeSi1-xAlx, Phys. Rev. B 64, 153106-153109 (2001).

24.     K. Kobayashi, T. Susaki, A. Fujimori, T. Tonogai, and H. Takagi: Disorder Effects in the Bipolaron System Ti4O7 Studied by Photoemission Spectroscopy, Europhys. Lett. 59, 868-874 (2002); cond-mat/9909189.

25.     K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Tuning of the Fano Effect through a Quantum Dot in an Aharonov-Bohm Interferometer, Phys. Rev. Lett. 88, 256806-256809 (2002); cond-mat/0202006.

26.     K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Observation-Dependent Decoherence in an Aharonov-Bohm Ring, Proceedings of The 7th International Symposium on Foundations of Quantum Mechanics In the Light of New Technology (eds. Y. A. Ono and K. Fujikawa, World Scientific), 237-240 (2002).

27.     K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Reduction of Quantum Decoherence in Non-Local Resistance Measurement (NPMS-5), Microelectronic Engineering 63, 53-56 (2002).

28.  K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Observation of an Enhanced Aharonov-Bohm effect (ISSP-Kashiwa 2001, invited poster), Journal of Physics and Chemistry of Solids 63, 1301-1305 (2002).

29.  K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Probe-Configuration-Dependent Decoherence in an Aharonov-Bohm Ring, Journal of the Physical Society of Japan 71, L2094-2097 (2002); cond-mat/0204186.

30.  K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Tunable Fano system: a quantum dot embedded in an Aharonov-Bohm ring (LT23, invited), Physica E 18, 56-59 (2003).

31.  K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: A Tunable Fano System Realized in a Quantum Dot in an Aharonov-Bohm Ring (ICPS-26), Physics of Semiconductors 2002, Institute of Physics Conference Series 171 (eds. A. R. Long, and J. H. Davies, Institute of Physics Publishing, Bristol), Q4.2 (2003).

32.     H. Aikawa, K. Kobayashi, S. Katsumoto, and Y. Iye: Suppression of Quantum Decoherence in Nonlocal Resistance Measurement (ICPS-26), Physics of Semiconductors 2002, Institute of Physics Conference Series 171 (eds. A. R. Long, and J. H. Davies, Institute of Physics Publishing, Bristol), P249 (2003).

33.     H. Aikawa, K. Kobayashi, S. Katsumoto, and Y. Iye: Suppression of Quantum Decoherence in an Aharonov-Bohm Ring (Localization 2002), Journal of the Physical Society of Japan 72, Suppl. A 5-6 (2003).

34.     K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Mesoscopic Fano effect in a quantum dot embedded in an Aharonov-Bohm ring, Phys. Rev. B 68, 235304 (2003); cond-mat/0309570.

35.     K. Kobayashi, H. Aikawa, S. Katsumoto, and Y. Iye: Mesoscopic Fano Effect through a QuantumDot in an Aharonov-Bohm Ring (EP2DS-15, invited), Physica E (accepted).

36.     H. Aikawa, K. Kobayashi, A. Sano, S. Katsumoto, and Y. Iye: Spin-flip Process and Quantum Decoherence in a Quantum Dot (EP2DS-15), Physica E (accepted).

37.     H. Aikawa, K. Kobayashi, A. Sano, S. Katsumoto, and Y. Iye: Observation of "Partial Coherence" in an Aharonov-Bohm Interferometer with a Quantum Dot, Phys. Rev. Lett. (accepted); cond-mat/0309084.

38.     H. Aikawa, K. Kobayashi, A. Sano, S. Katsumoto, and Y. Iye: Interference Effect in Multi-level Transport through a Quantum Dot, submitted; cond-mat/0312431.

39.     K. Kobayashi, H. Aikawa, A. Sano, S. Katsumoto, and Y. Iye: Fano Resonance in a Quantum Wire with a Side-coupled Quantum Dot, submitted; cond-mat/0311497.