MANY BODY EFFECTS AND INTERFERENCE IN QUANTUM-DOT SYSTEMS

• Project/Area Number: 19540338
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Kyoto University
• Principal Investigator: KAWAKAMI Norio Kyoto University, 大学院・理学研究科, 教授 (10169683)
• Project Period (FY): 2007 – 2008
• Project Status: Completed (Fiscal Year 2008)
• Budget Amount: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2008: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2007: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: メゾスコピック系・局在 / 量子ドット / 理論 / 量子輸送 / 超伝導 / アンドレーフ反射 / 近藤効果 / 干渉効果 / ナノ量子系

Research Abstract

本課題では量子ドットをベースとしたナノ量子複合系の電子相関と干渉効果の理論的研究を行った。特に、スピンおよび軌道自由度に起因する量子特性をアンダーソンモデルの厳密解、NCA近似などを用いて明らかにした。その結果、多軌道効果、近藤効果、干渉効果が織りなす新奇な輸送特性を見出した。さらに超伝導リードと結合した量子ドット系を考察し、近藤効果と超伝導相関の競合により生み出される多体効果を明らかにした。

Research Products

• [Journal Article] Andreev Reflection and the Kondo Effect in Side-Coupled Double Quantum Dots (2009)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Journal Title: J. Physics : Conference Series 150(in press)
  • Peer Reviewed
• [Journal Article] Nonequilibrium Transport through a Quantum Dot Coupled to Normal and Super conducting Leads (2009)
  • Author(s): Y. Yamada, Y. Tanaka and N. Kawakami
  • Journal Title: J. Physics : Conference Series 150 Pages: 22101-22101
  • Peer Reviewed
• [Journal Article] Nonequilibrium Transport through a Quantum Dot Coupled to Normal and Superconductins Leads (2009)
  • Author(s): Y. Yamada Y. Tanaka, N. Kawakami
  • Journal Title: Journal of Physics : Conference Series 150
  • Peer Reviewed
• [Journal Article] Andreev Transport through Side-Coupled Double Quantum Dots (2008)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Journal Title: Phys. Rev. B78
  • Peer Reviewed
• [Journal Article] Andreev transport through doublequantum dots ; Numerical renormalization group approach (2008)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Journal Title: Physica E40 Pages: 1618-1620
  • Peer Reviewed
• [Journal Article] Andreev Transport through Side-Coupled Double Quantum Dots (2008)
  • Author(s): Y. Tanaka, N. Kawakami, A. Oguri
  • Journal Title: Phys. Rev. B 78
  • Peer Reviewed
• [Journal Article] Andreev transport through double Quantum dots : Numerical renomalization group approach (2008)
  • Author(s): Y. Tanaka, N. Kawakami, A. Oguri
  • Journal Title: Physica E 40 Pages: 1618-1620
  • Peer Reviewed
• [Journal Article] Numerical Renormalization Group Approach to a Quantum Dot Coupled to Normal and Superconducting Leads (2007)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Journal Title: J. Phys. Soc. Jpn Vol.76
  • NAID: 110006350765
  • Peer Reviewed
• [Journal Article] Thermopower of Multiorbital Kondo Effect via Single Quantum Dot System at Finite Temperatures (2007)
  • Author(s): R.Sakano, T. Kita and N. Kawakami
  • Journal Title: J. Phys. Soc. Jpn. Vol.76
  • NAID: 110006350773
  • Peer Reviewed
• [Journal Article] Transport Properties of the Orbital Kondo Effect via Quantum DSystems with Plural Electrons (2007)
  • Author(s): R.Sakano, T.Kita, T. Ohashi, S. Suga and N. Kawakami
  • Journal Title: Phys. Stat. Sol. Vol.204 Pages: 492-495
• [Journal Article] Magnetic Field Effects on the Andreev Transport Through a Quantum Dot (2007)
  • Author(s): Y. Yamada, Y. Tanaka and N. Kawakami
  • Journal Title: Physica E40 Pages: 265-268
• [Journal Article] Numerical Renormalization Group Approach to a Quantum Dot Coupled to Normal and Superconducting Leads (2007)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Journal Title: J. Phys. Soc. Jpn. 76
  • NAID: 110006350765
  • Peer Reviewed
• [Journal Article] Thermopower of Multiorbital Kondo Effect via Single Quantum Dot System at Finite Temperatures (2007)
  • Author(s): Rui Sakano, Tomoko Kita and Norio Kawakami
  • Journal Title: J. Phys. Soc. Jpn. 76
  • NAID: 110006350773
  • Peer Reviewed
• [Journal Article] Transport Properties of the Orbital Kondo Effect via Quantum Dot Systems with Plural Electrons (2007)
  • Author(s): R.Sakano, T. Kita, T. Ohashi, S. Suga and N. Kawakami
  • Journal Title: Phys. Stat. So1. 204 Pages: 492-495
  • Peer Reviewed
• [Presentation] 有限バイアス電圧下における量子ドット系でのアンドレーエフ反射と近藤効果 (2009)
  • Author(s): 山田康博, 田中洋一, 川上則雄
  • Organizer: 日本物理学会「第64回年次大会」
  • Place of Presentation: 立教大(東京)
  • Year and Date: 2009-03-30
• [Presentation] 超伝導/常伝導リードに繋がれた量子ドット系における非平衡定常状態での近藤効果 (2008)
  • Author(s): 山田康博, 田中洋一, 川上則雄
  • Organizer: 日本物理学会「秋季大会」岩手大学
  • Place of Presentation: 盛岡
  • Year and Date: 2008-09-21
• [Presentation] T字型ダブルドット系における長距離的な近藤効果 (2008)
  • Author(s): 田中洋一, 川上則雄, 小栗章
  • Organizer: 日本物理学会「秋季大会」岩手大学
  • Place of Presentation: 盛岡
  • Year and Date: 2008-09-21
• [Presentation] 量子ドット系におけるアンドレーエフ反射と非平衡輸送特性II (2008)
  • Author(s): 山田康博, 田中洋一, 川上則雄
  • Organizer: 日本物理学会「第63回年次大会」
  • Place of Presentation: 近畿大学(大阪)
  • Year and Date: 2008-03-24
• [Presentation] T字型ダブルドット系におけるアンドレーエフ反射と近藤効果 (2008)
  • Author(s): 田中洋一, 川上則雄, 小栗章
  • Organizer: 日本物理学会「第63回年次大会」
  • Place of Presentation: 近畿大学(大阪)
  • Year and Date: 2008-03-24
• [Presentation] Andreev Reflection and the Kondo Effect in Side-Coupled Double Quantum Dots (2008)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Organizer: 25th International Conference on Low Temperature Physics (LT25)
  • Place of Presentation: Amsterdam, Netherland
• [Presentation] Nonequilibrium Transport through a Quantum Dot Coupled to Normal and Super conducting Leads (2008)
  • Author(s): Y. Yamada, Y. Tanaka and N. Kawakami
  • Organizer: 25th International Conference on Low Temperature Physics (LT25)
  • Place of Presentation: Amsterdam, Netherland
• [Presentation] Andreev Reflection and the Kondo Effect in Side-Coupled Double Quantum Dots (2008)
  • Author(s): Y. Tanaka, N. Kawakami, A. Osuri
  • Organizer: 25th International Conference on Low Temperature Physics
  • Place of Presentation: Amsterdam
• [Presentation] 量子ドット系におけるアンドレーエフ反射と非平衡輸送特性 (2007)
  • Author(s): 山田康博, 田中洋一, 川上則雄
  • Organizer: 日本物理学会「第62回年次大会」
  • Place of Presentation: 北海道大学(札幌)
  • Year and Date: 2007-09-24
• [Presentation] 超伝導/常伝導リードに繋がれたT字型ダブルドット系の輸送特性 (2007)
  • Author(s): 田中洋一, 川上則雄, 小栗章
  • Organizer: 日本物理学会「第62回年次大会」
  • Place of Presentation: 北海道大学(札幌)
  • Year and Date: 2007-09-24
• [Presentation] 軌道自由度を有した量子ドット系における非平衡近藤効果と輸送 (2007)
  • Author(s): 阪野塁, 川上則雄
  • Organizer: 日本物理学会「第62回年次大会」
  • Place of Presentation: 北海道大学(札幌)
  • Year and Date: 2007-09-22
• [Presentation] Orbital Kondo Effects in Quantum Dot Systems (2007)
  • Author(s): Norio Kawakami
  • Organizer: (invited) International Workshop on Physics and Mathematics of Interacting Quantum Systems in Low Dimensions
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2007-05-26
• [Presentation] Orbital Kondo Effects in Quantum Dot Systems (2007)
  • Author(s): Norio Kawakami
  • Organizer: Physics and Mathematics of Interacting Quantum Systems in Log Dimensions
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2007-05-26
• [Presentation] Andreev transport through doublequantum dots ; Numerical renormalization group approach (2007)
  • Author(s): Y. Tanaka, N. Kawakami and A. Oguri
  • Organizer: approach" Physica E40 (2008) 1618-1620 International Conference on Electronic Properties of Two-dimensional Systems and Modulated Semiconductor Structures
  • Place of Presentation: Genova, Italy
• [Presentation] Enhanced thermpower of Kondo effect in side-coupled quantum dot systems (2007)
  • Author(s): R. Sakano and N. Kawakami
  • Organizer: International Conference on Electronic Properties of Two-dimensional Systems and Modulated Semiconductor Structures
  • Place of Presentation: Genova, Italy
• [Remarks]
  • URL: http://cond.scphys.kyoto-u.ac.jp/