Markovian property of cooperative fluctuations investigated by light scattering spectroscopy

光散射光谱研究合作涨落的马尔可夫性质

• 批准号: 16340092
• 负责人: KINOSHITA Shuichi
• 金额: $ 10.18万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16340092/
• 关键词: Light scattering spectroscopy; Markovian dynamics; Fluctuation-dissipation theorem; Anharmonisity; 協同性; ストークス散乱; 反ストークス散乱; 応答関数; 協同的ゆらぎ

We have Ivestigated the Stokes to anti-Stokes intensity ratio for the low-frequency light scattering spectra of a paraelectric potassium dihydrogen phosphate (KDP) crystal. The usual relation determined by the Boltzmann factor holds at 293K. However the relation is not satisfied for the soft mode occurring for ω<30 cm-1 near the phase transition temperature, and the intensity ratio relative to the Boltzmann factor is about 0.94 at ω=15cm-1. The Markovian nature of the soft mode that introduces time-irreversibility may be essential for understanding the behavior of the mode like a classical fluctuation. Further investigation on the temperature dependence is needed for clarifying the evolution of the soft mode from microscopic quantum motions to the classical and macroscopic dynamics as temperature approaches Tc.We compare the present result of the soft mode with that of the cooperative rotational dynamics in liquid. In liquid carbon disulfide CS2, the intensity of Im(ω) changes with temperature below 50 cm-1. On the other hand, the deviation of the intensity ratio from the Boltzmann factor is observed only for ω<5cm-1 at 292K. This frequency region is much narrower than that where Im(ω) varies with temperature. The result is in contrast to the case of KDP where the deviation is observed almost in the same region where Im(ω) appreciably changes with temperature. This implies that although both the dynamics are dissipative, the degree of dissipation causing the Markovian nature of the soft mode is higher than that for the cooperative rotational dynamics. This may be related to the macroscopic character of the soft mode near Tc as a critical fluctuation.

本文研究了准电磷酸二氢钾晶体低频光散射光谱的Stokes与反Stokes强度比。通常由玻尔兹曼因子决定的关系在293K处成立。然而，当ω<30 cm-1时，在相变温度附近出现软模时，这种关系不满足，在ω=15cm-1时，相对于玻尔兹曼因子的强度比约为0.94。引入时间不可逆性的软模态的马尔可夫性质对于理解模态的行为如经典涨落可能是必不可少的。为了阐明当温度接近Tc时软模从微观量子运动到经典和宏观动力学的演化，需要进一步研究温度依赖性。我们将软模式的结果与液体中协同旋转动力学的结果进行了比较。在液态二硫化碳CS2中，在50 cm-1以下，Im（ω）的强度随温度的变化而变化。另一方面，在292K时，仅在ω<5cm-1时才观察到强度比与玻尔兹曼因子的偏差。这个频率区域比Im（ω）随温度变化的区域窄得多。结果与KDP的情况相反，在KDP的情况下，几乎在同一区域观察到偏差，其中Im（ω）随温度明显变化。这意味着尽管两种动力学都是耗散的，但导致软模式马尔可夫性质的耗散程度高于合作旋转动力学。这可能与Tc附近软模态作为临界涨落的宏观特征有关。

项目成果

Spatial and temporal fluctuations of diffraction spots from collidal crystals

胶体晶体衍射斑的空间和时间波动

• 发表时间: 2006
• 期刊: J.Surf.Sci.Tech. (In press)
• 作者: M.Ito;N.Tsuji;F.Itoh;H.Adachi;E.Arakawa;K.Namikawa;H.Nakao;Y.Murakami;Y.Taguchi;Y.Tokura;G.-Q.Zheng;橋爪 弘雄;G.-Q.Zheng;橋爪弘雄;S.Kawasaki;M.Yashima;A.V.Kornilov;G.-Q.Zheng;S.Kawasaki;M.Yashima;M.Yashima;J.Watanabe;Y.Kiyota;Y.Fujii;太田 仁;H.Yamada
• 通讯作者: H.Yamada

Evolution from Quantum to Classical Fluctuation in the Soft Mode of KH2PO4

KH2PO4 软模式从量子涨落到经典涨落的演化

• 发表时间: 2006
• 期刊: AIP Conference series (In press)
• 作者: M.Ito;N.Tsuji;F.Itoh;H.Adachi;E.Arakawa;K.Namikawa;H.Nakao;Y.Murakami;Y.Taguchi;Y.Tokura;G.-Q.Zheng;橋爪 弘雄;G.-Q.Zheng;橋爪弘雄;S.Kawasaki;M.Yashima;A.V.Kornilov;G.-Q.Zheng;S.Kawasaki;M.Yashima;M.Yashima;J.Watanabe
• 通讯作者: J.Watanabe

Non-Markovian Behavior of Material Response in Liquids

液体中材料响应的非马尔可夫行为

• 发表时间: 2006
• 期刊: AIP Conference series (In press)
• 作者: M.Ito;N.Tsuji;F.Itoh;H.Adachi;E.Arakawa;K.Namikawa;H.Nakao;Y.Murakami;Y.Taguchi;Y.Tokura;G.-Q.Zheng;橋爪 弘雄;G.-Q.Zheng;橋爪弘雄;S.Kawasaki;M.Yashima;A.V.Kornilov;G.-Q.Zheng;S.Kawasaki;M.Yashima;M.Yashima;J.Watanabe;Y.Kiyota
• 通讯作者: Y.Kiyota

Forroelastic Domain Formation Mechanism Investigated by Simultaneous Measurements of Light Deflection and Brillouin Scattering

同时测量光偏转和布里渊散射研究弹性域形成机制

• 发表时间: 2006
• 期刊: Forroelectrics (In press)
• 作者: Y.Fujii;S.Yoshioka;S.Kinoshita
• 通讯作者: S.Kinoshita

Ferroelastic Domain Foramtion Mechanism Investigated by Simultaneous Measurements of Light Deflection and Brillouin Scattering

同时测量光偏转和布里渊散射研究铁弹性域形成机制

• 发表时间: 2006
• 期刊: Ferroelectrics (In press)
• 作者: M;Kimata;K;Koyama;H;Ohra;Y;Oshima;M;Motokawa;H;Nishikawa;K;Kikuchi;I;Ikemoto;Y.Kiyota et al.;M.Kimata;M.Kimata;Y.Fujii et al.
• 通讯作者: Y.Fujii et al.