2001 Fiscal Year Annual Research Report

半導体二次元界面に於ける励起子集団のコヒーレント伝播と多体効果

Research Project

Project/Area Number	11215208
Research Institution	Osaka City University
Principal Investigator	唐沢力大阪市立大学, 大学院・理学研究科, 教授 (90106336)
Co-Investigator(Kenkyū-buntansha)	飯田武大阪市立大学, 大学院・理学研究科, 教授 (80047191) 中山正昭大阪市立大学, 大学院・工学研究科, 教授 (30172480) 赤井一郎大阪市立大学, 大学院・理学研究科, 助教授 (20212392) 鈴木正人大阪市立大学, 大学院・理学研究科, 講師 (70254381) 溝口幸司大阪市立大学, 大学院・工学研究科, 助教授 (10202342)
Keywords	高密度励起子 / BiI_3積層欠陥励起子 / 層状結晶(GaSe,PbI_2) / 励起子の超流動性 / GaAs / AlAs超格子 / タイプ-II超格子・量子井戸 / Bose-Einstein統計性 / 励起子系での巨視的量子現象
Research Abstract	半導体二次元界面における光誘起高密度励起子集団の特異な振舞いに関して以下の成果を得た。 1.層状結晶BiI_3中の積層不整界面に局在する擬二次元励起子(SFE)を、ピコ秒色素レーザーで高密度に生成し、ポンプ・プローブ吸収、ポイント励起発光、2光束空間分離励起縮退四光波混合などのスペクトルに時間・空間分解分光法を適用してその空間的挙動を調べた。その結果、ある密度以上でコヒーレントに伝播する励起子成分を検出した。この成分はSFE系が長距離秩序を持った位相空間凝縮(ボーズ凝縮)相であると結論づけた。またGaSe、PbI_2結晶などでは励起子同士の非弾性散乱が分子形成とともに高密度状態を特徴づけていることも明らかにした。 2.GaAs/AlAsタイプ-II超格子では励起子寿命がμs域と長いために、励起子系の冷却効率が高い。この長寿命性に着目し、GaAs(3.5nm)/AlAs(3.5nm)タイプ-II超格子試料における発光減衰過程での時間分解スペクトルの詳細な測定を行った。発光バンド形状の解析から、1x10^<10>cm^<-2>程度の励起子密度以上で励起子分子密度が閾値特性を有して顕著に増大し、さらにその閾値特性が、励起強度と温度に大きく依存することを見出した。この結果を統計力学的に解析し、励起子-励起子分子系においてBose-Einstein統計性が発現しているという結論を得た。 3.理論的取組みとして、タイプII量子井戸中の擬二次元励起子系の秩序状態とその相転移について調べた。この系には位相の空間構造に依存して、励起子の超流動に伴う相(S相)と伴なわない相(I相)およびノーマル相(N相)が存在すること、およびS相とN相、I相とN相の間の相転移機構として、各々defect-mediated Kosterlitz-Thouless転移、巨視的長さのソリトン励起を導入し、相転移の温度依存性を明らかにした。

Research Products
(25 results)

All Other

All Publications (25 results)

[Publications] H.Ichida, M.Nakayama: "Evidence for quantum statistics of the exciton-biexciton system in a GaAs/AlAs type-II superlattice"Phys.Rev.. B-63. 195316-1-195316-6 (2001)
[Publications] A.Tanji, I.Akai, T.Karasawa, V.F.Aguekian: "Spatial evolution of inelastic scattering of high-density excitons in GaSe crystals"J.Lumin.. 94-95. 365-368 (2001)
[Publications] H.Ichida, M.Nakayama: "Boson characteristics of the exciton-biexciton system in a GaAs/AlAs type-II superlattice"J.Lumin.. 94-95. 379-382 (2001)
[Publications] K.Bando, I.Akai, T.Karasawa, K.Maehashi, H.Nakashima: "Dynamical processes on high density indirect and direct Excitons in Al_xGa_<1-x>As/AlAs quantum wires"J.Lumin.. 94-95. 389-392 (2001)
[Publications] Y.Shirasaka, A.Tanji, I.Akai, T.Karasawa: "Coherent Motion of High-Density Exciton Masses at a Quasi Two-Dimensional Interface in BiI_3"J.Lumin.. 94-95. 433-436 (2001)
[Publications] M.Suzuki: "Lattice-relaxation and energy-transfer of Frenkel and charge-transfer excitons in molecular crystals"Int.J.Modern Phys. B-15. 3681-3684 (2001)
[Publications] K.Bando, I.Akai, T.Karasawa, K.Inoue, H.Nakashima: "High density excitation effects on excitons and electron-hole pairs in Al_xGa_<1-x>As/AlAs quantum wires"Int.J.Modern Phys.. B-15. 3757-3760 (2001)
[Publications] H.Ichida, K.Tsuji, K.Mizoguchi, H.Nishimura, M.Nakayama: "Transition from biexcitons to electron-hole plasma in photoluminescence properties of a GaAs/AlAs multiple-quantum-well structure"Int.J.Modern Phys.. B-15. 3793-3796 (2001)
[Publications] T.Iida, M.Tsubota: "Order formation and elementary excitations in type-II quantum well exciton system"Int.J.Modern Phys.. B-15. 3801-3804 (2001)
[Publications] Y.Kawasumi, I.Akai, T.Karasawa: "Photoluminescence and dynamics of excitons in Alq_3 single crystals"Int.J.Modern Phys.. B-15. 3825-3828 (2001)
[Publications] H.Nitta, M.Suzuki, T.Iida: "Multistable natures and photoinduced charge-separation in hole-doped states of strongly coupled electron-phonon systems"Int.J.Modern Phys.. B-15. 3904-3907 (2001)
[Publications] M.Shin'i, M.Suzuki: "Successive structural changes and their dynamics in multi-stepwised potential-crossing systems via multi-photoexcitations"Int.J.Modern Phys.. B-15. 3956-3959 (2001)
[Publications] M.Suzuki: "Photoinduced polymerization in crystalline C60 via multi-photoexcitation:lattice-relaxation and energy-transfer of excitons"Proc.AIP Conf.(Nanonetwork Materials:Fullerenes,Nanotubes,and Related Systems. 590. 401-404 (2001)
[Publications] K.Mizoguchi, H.Takeuchi, T.Hino, M.Nakayama: "Finite-size effects on coherent folded acoustic phonons in GaAs/AlAs superlattices"J.Phys.:Condens.Matter. 14. L103 (2002)
[Publications] H.Takeuchi, K.Mizoguchi, M.Nakayama, K.Kuroyanagi, T.Aida, M.Nakajima, H.Harima: "Simultaneous observation of coherent GaSb-like and AlSb-like longitudinal optical phonons in GaSb/AlSb superlattices"J.Phys.Soc.Jpn.. 70. 2596 (2001)
[Publications] H.Takeuchi, K.Mizoguchi, M.Nakayama: "Coherent phonon-plasmon coupled modes in(InAs)_1/(GaAs)_m strained-layer superlattices"Proceedings of the 10th International Conference on Narrow Gap Semiconductors and Related Small Energy Phenomena,IPAP Conf.. Series2. 207 (2001)
[Publications] A.Saitoh, T.Komatsu, T.Karasawa, H.Ohtake, T.Suemoto: "Raman scattering under hydrostatic pressures in layered BiI_3 and SbI_3 crystals"phys.stat.sol.. (b)226. 357-367 (2001)
[Publications] Y.Shirasaka, H.Mino, T.Kawai, I.Akai, T.Karasawa: "Spatial behavior of exciton-polariton masses in a layered crystal BiI_3"Int.J.Modern Phys.. B-15. 3960-3964 (2001)
[Publications] H.Takeuchi, K.Mizoguchi, T.Hino, M.Nakayama: "Coherent folded acoustic phonons in GaAs/AlAs superlattices with limited periodicity"Physica. B(印刷中). (2002)
[Publications] H.Takeuchi, K.Mizoguchi, T.Aida, M.Nakayama: "Effects of a miniband structure on coherent LO phonon-plasmon coupled modes in an(InAs)_1/(GaAs)_<30> strained-layer superlattice"Physica. B(印刷中). (2002)
[Publications] T.Karasawa, A.Tanji, I.Akai: "Photoinduced high-density phase of exciton-polariton masses and their coherent propagation at stacking fault interface in BiI_3"Phase Transitions. (印刷中). (2002)
[Publications] K.Bnado, I.Aakai, T.Karasawa, K.Maehashi, H.Nakashima: "High-density effects on the exciton systems and their dynamical behavior in Al_xGa_<1-x>As/AlAs quantum wires"Phase Transitions. (印刷中). (2002)
[Publications] T.Iida, M.Tsubota: "Order state and superfluidity of quasi-two-dimensional excitons in type-II quantum wells"Phase Transitions. (印刷中). (2002)
[Publications] M.Shin'i, M.Suzuki: "Hierarchic natures and dynamics of photoinduced structural phase transition in non-degenerate charge density wave states via successive photoexcitations"Phase Transitions. (印刷中). (2002)
[Publications] M.Nakayama, H.Ichida: "Quantum statistics behavior of the exciton-biexciton system in GaAs/AlAs type-II superlattices"Phase Transitions. (印刷中). (2002)

2001 Fiscal Year Annual Research Report

半導体二次元界面に於ける励起子集団のコヒーレント伝播と多体効果

Principal Investigator

唐沢 力 大阪市立大学, 大学院・理学研究科, 教授 (90106336)

Research Products

[Publications] H.Ichida, M.Nakayama: "Evidence for quantum statistics of the exciton-biexciton system in a GaAs/AlAs type-II superlattice"Phys.Rev.. B-63. 195316-1-195316-6 (2001)

[Publications] A.Tanji, I.Akai, T.Karasawa, V.F.Aguekian: "Spatial evolution of inelastic scattering of high-density excitons in GaSe crystals"J.Lumin.. 94-95. 365-368 (2001)

[Publications] H.Ichida, M.Nakayama: "Boson characteristics of the exciton-biexciton system in a GaAs/AlAs type-II superlattice"J.Lumin.. 94-95. 379-382 (2001)

[Publications] K.Bando, I.Akai, T.Karasawa, K.Maehashi, H.Nakashima: "Dynamical processes on high density indirect and direct Excitons in Al_xGa_<1-x>As/AlAs quantum wires"J.Lumin.. 94-95. 389-392 (2001)

[Publications] Y.Shirasaka, A.Tanji, I.Akai, T.Karasawa: "Coherent Motion of High-Density Exciton Masses at a Quasi Two-Dimensional Interface in BiI_3"J.Lumin.. 94-95. 433-436 (2001)

[Publications] M.Suzuki: "Lattice-relaxation and energy-transfer of Frenkel and charge-transfer excitons in molecular crystals"Int.J.Modern Phys. B-15. 3681-3684 (2001)

[Publications] K.Bando, I.Akai, T.Karasawa, K.Inoue, H.Nakashima: "High density excitation effects on excitons and electron-hole pairs in Al_xGa_<1-x>As/AlAs quantum wires"Int.J.Modern Phys.. B-15. 3757-3760 (2001)

[Publications] H.Ichida, K.Tsuji, K.Mizoguchi, H.Nishimura, M.Nakayama: "Transition from biexcitons to electron-hole plasma in photoluminescence properties of a GaAs/AlAs multiple-quantum-well structure"Int.J.Modern Phys.. B-15. 3793-3796 (2001)

[Publications] T.Iida, M.Tsubota: "Order formation and elementary excitations in type-II quantum well exciton system"Int.J.Modern Phys.. B-15. 3801-3804 (2001)

[Publications] Y.Kawasumi, I.Akai, T.Karasawa: "Photoluminescence and dynamics of excitons in Alq_3 single crystals"Int.J.Modern Phys.. B-15. 3825-3828 (2001)

[Publications] H.Nitta, M.Suzuki, T.Iida: "Multistable natures and photoinduced charge-separation in hole-doped states of strongly coupled electron-phonon systems"Int.J.Modern Phys.. B-15. 3904-3907 (2001)

[Publications] M.Shin'i, M.Suzuki: "Successive structural changes and their dynamics in multi-stepwised potential-crossing systems via multi-photoexcitations"Int.J.Modern Phys.. B-15. 3956-3959 (2001)

[Publications] M.Suzuki: "Photoinduced polymerization in crystalline C60 via multi-photoexcitation:lattice-relaxation and energy-transfer of excitons"Proc.AIP Conf.(Nanonetwork Materials:Fullerenes,Nanotubes,and Related Systems. 590. 401-404 (2001)

[Publications] K.Mizoguchi, H.Takeuchi, T.Hino, M.Nakayama: "Finite-size effects on coherent folded acoustic phonons in GaAs/AlAs superlattices"J.Phys.:Condens.Matter. 14. L103 (2002)

[Publications] H.Takeuchi, K.Mizoguchi, M.Nakayama, K.Kuroyanagi, T.Aida, M.Nakajima, H.Harima: "Simultaneous observation of coherent GaSb-like and AlSb-like longitudinal optical phonons in GaSb/AlSb superlattices"J.Phys.Soc.Jpn.. 70. 2596 (2001)

[Publications] H.Takeuchi, K.Mizoguchi, M.Nakayama: "Coherent phonon-plasmon coupled modes in(InAs)_1/(GaAs)_m strained-layer superlattices"Proceedings of the 10th International Conference on Narrow Gap Semiconductors and Related Small Energy Phenomena,IPAP Conf.. Series2. 207 (2001)

[Publications] A.Saitoh, T.Komatsu, T.Karasawa, H.Ohtake, T.Suemoto: "Raman scattering under hydrostatic pressures in layered BiI_3 and SbI_3 crystals"phys.stat.sol.. (b)226. 357-367 (2001)

[Publications] Y.Shirasaka, H.Mino, T.Kawai, I.Akai, T.Karasawa: "Spatial behavior of exciton-polariton masses in a layered crystal BiI_3"Int.J.Modern Phys.. B-15. 3960-3964 (2001)

[Publications] H.Takeuchi, K.Mizoguchi, T.Hino, M.Nakayama: "Coherent folded acoustic phonons in GaAs/AlAs superlattices with limited periodicity"Physica. B(印刷中). (2002)

[Publications] H.Takeuchi, K.Mizoguchi, T.Aida, M.Nakayama: "Effects of a miniband structure on coherent LO phonon-plasmon coupled modes in an(InAs)_1/(GaAs)_<30> strained-layer superlattice"Physica. B(印刷中). (2002)

[Publications] T.Karasawa, A.Tanji, I.Akai: "Photoinduced high-density phase of exciton-polariton masses and their coherent propagation at stacking fault interface in BiI_3"Phase Transitions. (印刷中). (2002)

[Publications] K.Bnado, I.Aakai, T.Karasawa, K.Maehashi, H.Nakashima: "High-density effects on the exciton systems and their dynamical behavior in Al_xGa_<1-x>As/AlAs quantum wires"Phase Transitions. (印刷中). (2002)

[Publications] T.Iida, M.Tsubota: "Order state and superfluidity of quasi-two-dimensional excitons in type-II quantum wells"Phase Transitions. (印刷中). (2002)

[Publications] M.Shin'i, M.Suzuki: "Hierarchic natures and dynamics of photoinduced structural phase transition in non-degenerate charge density wave states via successive photoexcitations"Phase Transitions. (印刷中). (2002)

[Publications] M.Nakayama, H.Ichida: "Quantum statistics behavior of the exciton-biexciton system in GaAs/AlAs type-II superlattices"Phase Transitions. (印刷中). (2002)

唐沢力大阪市立大学, 大学院・理学研究科, 教授 (90106336)