Eto, Mikio



Faculty of Science and Technology, Department of Physics (Yagami)



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Career 【 Display / hide

  • 1990.04

    日本学術振興会 ,特別研究員

  • 1992.04

    慶應義塾大学理工学部(物理学科) ,助手

  • 1997.04

    慶應義塾大学理工学部(物理学科) ,専任講師

  • 1998.04

    兼北海道大学量子界面エレクトロニクス研究センター ,客員助教授

  • 1999.04

    guest researcher at Delft University of Technology, the Netherlands

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Academic Background 【 Display / hide

  • 1986.03

    The University of Tokyo, Faculty of Science, 物理学科

    University, Graduated

  • 1988.03

    The University of Tokyo, Graduate School, Division of Science, 物理学専攻

    Graduate School, Completed, Master's course

  • 1990.09

    The University of Tokyo, Graduate School, Division of Science, 物理学専攻

    Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • 理学 , The University of Tokyo, 1990.09


Research Areas 【 Display / hide

  • Natural Science / Semiconductors, optical properties of condensed matter and atomic physics


Books 【 Display / hide

  • Quantum Hybrid Electronics and Materials

    Yoshiro Hirayama, Kazuhiko Hirakawa, Hiroshi Yamaguchi (eds.), Springer, 2022,  Page: 341

    Scope: chapter "Novel Phonon Generator and Photon Detector by Single Electron Transport in Quantum Dots",  Contact page: 235–256 Original author: Mikio Eto and Rin Okuyama

  • Physics of Quantum Rings

    Vladimir M. Fomin (ed.), Springer, 2018,  Page: 435

    Scope: chapter "Optical Aharonov-Bohm Oscillations with Disorder Effects and Wigner Molecule in a Single GaAs/AlGaAs Quantum Ring",  Contact page: 231–254 Original author: K. Kyhm, H. D. Kim, R. Okuyama, M. Eto, K. C. Je, R. A. Taylor, G. Nogues, L. S. Dang, A. A. L. Nicholet, M. Potemski, J. S. Kim & J. D. Song

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    The optical Aharonov-Bohm effect in a single quantum ring is associated with disorder effects. In the presence of structure anisotropy, localisation, internal electric field, and impurity scattering, optical Aharonov-Bohm oscillations of an electron-hole pair become modulated. Additionally, provided that a strongly correlated exciton pair is formed in a single quantum ring similar to the Wigner molecule, novel oscillations can be observed for increasing magnetic field. In this case, the biexciton emission energy changes abruptly at transition magnetic fields with a fractional oscillation period compared to that of the exciton, the so-called fractional optical Aharonov-Bohm oscillations.

  • パリティ物理教科書シリーズ、量子力学I

    ETO MIKIO, 丸善出版, 2013.10

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  • 物性物理学ハンドブック

    ETO MIKIO, 朝倉書店, 2012.04

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  • Comprehensive Semiconductor Science and Technology

    M. Eto and H. Kamimura, Elsevier, 2011.02

    Contact page: 77-112

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Papers 【 Display / hide

  • Kondo Effect and Phase Measurement in Double Quantum Dot in Parallel

    Zhang Y., Sakano R., Eto M.

    Journal of the Physical Society of Japan (Journal of the Physical Society of Japan)  91 ( 1 )  2022.01

    ISSN  00319015

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    We propose a double quantum dot (DQD) in parallel as a tractable model for a mesoscopic ring with an embedded quantum dot (QD), which functions as a QD interferometer. One of the DQDs (QD 1) represents the embedded QD with energy level ϵ1 and Coulomb interaction U, whereas the other (QD 2) acts as a reference arm with an enlarged linewidth due to the tunnel coupling to external leads. The conductance at temperature T = 0 is formulated simply in terms of the retarded and advanced Green's functions of the DQD, which are exactly evaluated using the Bethe ansatz solution for the Kondo effect. Using this model, we address two controversial issues concerning the QD interferometer. The first issue concerns the shape of the conductance peak as a function of ϵ1. We show a crossover from an asymmetric Fano resonance (Fano-Kondo effect) to a symmetric Breit-Wigner resonance (Kondo plateau) in the absence (presence) of U, by decreasing the connection between the QDs through the leads. The second is on the measurement of the transmission phase shift through QD 1 by a "double-slit experiment", which is impossible in the two-terminal geometry because of the Onsager's reciprocity theorem. In a three-terminal geometry, we discuss a possible observation of phase locking at π=2 in the Kondo regime.

  • Fano-Kondo resonance versus Kondo plateau in an Aharonov-Bohm ring with an embedded quantum dot

    Eto M., Sakano R.

    Physical Review B (Physical Review B)  102 ( 24 )  2020.12

    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  24699950

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    We theoretically examine the transport through an Aharonov-Bohm ring with an embedded quantum dot (QD), the so-called QD interferometer, to address two controversial issues regarding the shape of the Coulomb peaks and measurement of the transmission phase shift through a QD. We extend a previous model [B. R. Bulka and P. Stefański, Phys. Rev. Lett. 86, 5128 (2001)PRLTAO0031-900710.1103/PhysRevLett.86.5128; W. Hofstetter, J. König, and H. Schoeller, ibid. 87, 156803 (2001)PRLTAO0031-900710.1103/PhysRevLett.87.156803] to consider multiple conduction channels in two external leads, L and R. We introduce a parameter pα (|pα|≤1) to characterize a connection between the two arms of the ring through lead α (=L, R), which is the overlap integral between the conduction modes coupled to the two arms. First, we study the shape of a conductance peak as a function of energy level in the QD, in the absence of electron-electron interaction U. We show an asymmetric Fano resonance for |pL,R|=1 in the case of single conduction channel in the leads and an almost symmetric Breit-Wigner resonance for |pL,R|<0.5 in the case of multiple channels. Second, the Kondo effect is taken into account by the Bethe ansatz exact solution in the presence of U. We precisely evaluate the conductance at temperature T=0 and show a crossover from an asymmetric Fano-Kondo resonance to the Kondo plateau with changing pL,R. Our model is also applicable to the multiterminal geometry of the QD interferometer. We discuss the measurement of the transmission phase shift through the QD in a three-terminal geometry by a "double-slit experiment."We derive an analytical expression for the relation between the measured value and the intrinsic value of the phase shift.

  • Topological classification of the single-wall carbon nanotube

    Okuyama R., Izumida W., Eto M.

    Physical Review B (Physical Review B)  99 ( 11 )  2019.03

    Research paper (scientific journal), Last author, Accepted,  ISSN  24699950

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    © 2019 American Physical Society. The single-wall carbon nanotube (SWNT) can be a one-dimensional topological insulator, which is characterized by a Z-topological invariant, winding number. Using the analytical expression for the winding number, we classify the topology for all possible chiralities of SWNTs in the absence and presence of a magnetic field, which belongs to the topological categories of BDI and AIII, respectively. We find that the majority of SWNTs are nontrivial topological insulators in the absence of a magnetic field. In addition, the topological phase transition takes place when the band gap is closed by applying a magnetic field along the tube axis, in all the SWNTs except armchair nanotubes. The winding number determines the number of edge states localized at the tube ends by the bulk-edge correspondence, the proof of which is given for SWNTs in general. This enables the identification of the topology in experiments.

  • Fano Resonance in Transport Through Double Quantum Dot in Parallel

    Zhang Y., Eto M.

    Physica Status Solidi (B) Basic Research (Physica Status Solidi (B) Basic Research)  256 ( 6 )  2019

    ISSN  03701972

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    © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The transport properties of double quantum dot (DQD) in parallel are theoretically examined. This system simulates a mesoscopic ring with an embedded quantum dot, so-called Aharonov–Bohm (AB) interferometer, by enlarging the line width in one of the quantum dots. We find that: 1) the Coulomb peak shows an asymmetric shape of Fano resonance when the DQD is coupled to external leads with single conduction channel; 2) the peak becomes more symmetric for the leads with multiple channels; and 3) the resonant shape is characterized by a single parameter which is determined by the structure of the leads. Our theory may explain the experimental results on the transport through the AB interferometer; an asymmetric Fano resonance was observed by one group while a symmetric Breit–Wigner resonance was observed by the other groups.

  • Light Controlled Optical Aharonov-Bohm Oscillations in a Single Quantum Ring

    Kim H., Park S., Okuyama R., Kyhm K., Eto M., Taylor R., Nogues G., Dang L., Potemski M., Je K., Kim J., Kyhm J., Song J.

    Nano Letters (Nano Letters)  18 ( 10 ) 6188 - 6194 2018.10

    ISSN  15306984

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    © 2018 American Chemical Society. We found that optical Aharonov-Bohm oscillations in a single GaAs/GaAlAs quantum ring can be controlled by excitation intensity. With a weak excitation intensity of 1.2 kW cm -2 , the optical Aharonov-Bohm oscillation period of biexcitons was observed to be half that of excitons in accordance with the period expected for a two-exciton Wigner molecule. When the excitation intensity is increased by an order of magnitude (12 kW cm -2 ), a gradual deviation of the Wigner molecule condition occurs with decreased oscillation periods and diamagnetic coefficients for both excitons and biexcitons along with a spectral shift. These results suggest that the effective orbit radii and rim widths of electrons and holes in a single quantum ring can be modified by light intensity via photoexcited carriers, which are possibly trapped at interface defects resulting in a local electric field.

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Papers, etc., Registered in KOARA 【 Display / hide

Presentations 【 Display / hide

  • トポロジーによるカーボンナノチューブの分類

    奥山倫, 泉田渉, 江藤幹雄

    日本物理学会第73回年次大会 (東京理科大学野田キャンパス、野田) , 


    Oral presentation (general)

  • Topological classification of single-wall carbon nanotubes

    R. Okuyama, W. Izumida, and Mikio Eto

    International symposium on nanoscale transport and photonics 2017 (Atsugi, Japan) , 


    Poster presentation

  • カーボンナノチューブにおけるトポロジカル相転移II

    奥山倫, 泉田渉, 江藤幹雄

    日本物理学会2017年秋季大会 (岩手大学、盛岡) , 


    Oral presentation (general)

  • Topological properties in single-wall carbon nanotube: effective one-dimensional lattice model approach

    R. Okuyama, W. Izumida, and Mikio Eto

    International Symposium on Hybrid Quantum Systems 2017 (Miyagi-Zao, Japan) , 


    Oral presentation (general)

  • Topological properties of single-wall carbon nanotube

    R. Okuyama, W. Izumida, and Mikio Eto

    7th Summer School on Semiconductor/Superconducting Quantum Coherence Effect and Quantum Information (Izu, Japan) , 


    Oral presentation (general)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Novel detector of THz light using an array of quantum dots


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

Awards 【 Display / hide

  • Outstanding Referee for the Journals of the American Physical Society

    Mikio Eto, 2017.01, The American Physical Society

    Type of Award: International academic award (Japan or overseas)

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Courses Taught 【 Display / hide











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Memberships in Academic Societies 【 Display / hide

  • Japanese Physical Society, 


Committee Experiences 【 Display / hide

  • 2016.04

    会誌編集委員, 日本物理学会

  • 2015.04

    編集委員, 雑誌「固体物理」(アグネ技術センター発行)

  • 2014.06

    プログラム委員, 21st International Conference on Electronic Properties of Two-Dimensional Systems

  • 2014.06

    組織委員会委員, 東京大学物性研究所、国際ワークショップ "New Perspectives in Spintronic and Mesoscopic Physics"

  • 2008.10

    代表, 日本物理学会 物性領域4

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