1998 Fiscal Year Annual Research Report

微小強磁性トンネル接合に於けるクーロン・ブロッケイドの基礎理論

Research Project

Project/Area Number	10130221
Research Institution	Nara Women's University
Principal Investigator	岩渕修一奈良女子大学, 理学部, 助教授 (40294277)
Keywords	メゾスコピック系の物理 / クーロン・ブロッケイド / 微小強磁性トンネル接合 / トンネル磁気抵抗 / 電磁場環境効果 / エネルギー散逸と量子力学 / 高次のトンネル効果 / 非平衡グリーン関数
Research Abstract	本年度は、以下の2項目に関して研究を実施した。 (1) 任意の外部環境インピーダンスを有する強磁性2重トンネル接合の理論を (a) 非平衡グリーン関数による高次のトンネル素過程の考慮 (b) 電磁場環境効果をフィードバックさせたアイランドの電荷状態の自己無撞着な記述の2点を考慮して定式化し磁気トンネル電流、磁気抵抗変化率の表式を求めた。 (2) 上記理論に基づき、微小強磁性2重トンネル接合に於ける任意の環境インピーダンスでのトンネル電流、有効磁気抵抗の振る舞いを解析的に評価し、この系でのクーロン・プロッケイドの物理を明確にするとともに強磁性トンネル接合での単電子トンネル現象の制御に関わるインピーダンス変調効果について検討した。

Research Products

(8 results)

All Other

All Publications (8 results)

[Publications] S.Iwabuchi,T.Tanamoto and R.Kitawaki: "Coulomb blockade and enhancement of magnetoresistance change in ultrasmall ferro-magnetic tunnel junctions" Physica B. 249. 276-280 (1998)
[Publications] F.Wakaya,F.Yoshioka,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Single-electron tunneling device with variable environmental impedance" Semicond.Sci.technol.13. A107-A110 (1998)
[Publications] F.Wakaya,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Possible control method for single-electron tunneling based on environmental-impedance modulation" Appl.Phys.Lett.74. 135-137 (1999)
[Publications] R.Kitawaki,F.Wakaya and S.Iwabuchi: "Coulomb blockade and enhancement of magnetoresistance change in ultrasmall ferro-magnetic double junctions" Quantum Coherence and Decoherence(North-Holland)ed.by K.Fujikawa and Y.A.Ono. Delta Series(印刷中). (1999)
[Publications] F.Wakaya,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Effects of asymmetric environment on the island charge state of single-electron tran-sistors" Physica B. (印刷中). (1999)
[Publications] S.Iwabuchi and F.Wakaya: "Enhancement of magnetoresistance change of ultrasmall ferromagnetic tunnel junc-tions in Coulomb blockade regime" Phys.Rev.B(印刷中). (1999)
[Publications] 岩渕修一: "メゾスコピック系の物理" 丸善, 152 (1998)
[Publications] S.Iwabuchi: "Coulomb blockade and electromagnetic environment effect in normal,superconducting and ferromagnetic ultrasmall tunnel junctions (Chap.4) in Optical and Electronic Process of Nano-Matters ed.by M.Ootsu" Kluwer Academic Publishers, 40 (1999)

1998 Fiscal Year Annual Research Report

微小強磁性トンネル接合に於けるクーロン・ブロッケイドの基礎理論

Principal Investigator

岩渕 修一 奈良女子大学, 理学部, 助教授 (40294277)

Research Products

[Publications] S.Iwabuchi,T.Tanamoto and R.Kitawaki: "Coulomb blockade and enhancement of magnetoresistance change in ultrasmall ferro-magnetic tunnel junctions" Physica B. 249. 276-280 (1998)

[Publications] F.Wakaya,F.Yoshioka,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Single-electron tunneling device with variable environmental impedance" Semicond.Sci.technol.13. A107-A110 (1998)

[Publications] F.Wakaya,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Possible control method for single-electron tunneling based on environmental-impedance modulation" Appl.Phys.Lett.74. 135-137 (1999)

[Publications] R.Kitawaki,F.Wakaya and S.Iwabuchi: "Coulomb blockade and enhancement of magnetoresistance change in ultrasmall ferro-magnetic double junctions" Quantum Coherence and Decoherence(North-Holland)ed.by K.Fujikawa and Y.A.Ono. Delta Series(印刷中). (1999)

[Publications] F.Wakaya,S.Iwabuchi,H.Higurashi,Y.Nagaoka and K.Gamo: "Effects of asymmetric environment on the island charge state of single-electron tran-sistors" Physica B. (印刷中). (1999)

[Publications] S.Iwabuchi and F.Wakaya: "Enhancement of magnetoresistance change of ultrasmall ferromagnetic tunnel junc-tions in Coulomb blockade regime" Phys.Rev.B(印刷中). (1999)

[Publications] 岩渕修一: "メゾスコピック系の物理" 丸善, 152 (1998)

[Publications] S.Iwabuchi: "Coulomb blockade and electromagnetic environment effect in normal,superconducting and ferromagnetic ultrasmall tunnel junctions (Chap.4) in Optical and Electronic Process of Nano-Matters ed.by M.Ootsu" Kluwer Academic Publishers, 40 (1999)

岩渕修一奈良女子大学, 理学部, 助教授 (40294277)