Study of Intrinsic Localized Modes in Quantum Lattices

量子晶格中本征局域模式的研究

• 批准号: 18340086
• 负责人: SATO Masayuki
• 金额: $ 10.09万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18340086/
• 关键词: Intrinsic Localized Modes; Terahertz Spectroscopy; Far-infrared Spectroscopy; Four-wave Mixing Spectroscopy; Laser Spectroscopy; Lattice Vibration; Dielectric materials

A THz nonlinear four wave mixing spectrometer has been developed for studies of intrinsic localized modes of phonon vibration in solids. A FIR laser excited by a TEA laser, a CW FIR laser excited by a carbon dioxide gas laser, a titanium-sapphire laser, Fourier spectrometers have been modified, converted and upgraded. Those equipments have been operated.From theoretical consideration of the time-resolved four wave mixing spectroscopy using above lasers, it has been concluded that the frequency of the FIR laser has to be coincide with a n-th harmonics of a repetition frequency of the titanium-sapphire laser. A cavity length of the titanium sapphire laser must be adjusted to achieve the coincidence of those frequencies. The adjustment of the cavity length is estimated to be within 100mm, and the adjustment with such length will be possible. In this study, we haven't achieved a full development of the four-wave mixing spectrometer with synchronized FIR and titanium-sapphire lasers, partia … More lly because of this unexpected synchronizing problem and because of a failure of an excitation laser of the titanium laser. However, we have been expecting that the development will be completed and four-wave mixing spectra of solids will be measured. It is also expected that problems of phase transition phenomena of solids like dielectrics will be well studied from the point of view of the nonlinear intrinsic localized modes.Intrinsic localized modes based on a 3rd order nonlinearity have been experimentally observed in antiferromagnets and MEMS oscillators. Measurements of four wave-mixing spectra and discovery of sideband resonant structure are very powerful tools in those studies. In this study, we have speculated that the origin of the sideband resonant structure is the fact that the cross nonlinear resonant frequency shift is always larger than the auto nonlinear resonant frequency shift. We have also speculating that the same mechanism keeps the shape of such nonlinear localized modes. We have confirmed that similar sideband structure appears for the intrinsic localized modes based on a 2nd order nonlinearity, that is expected for lattice vibrations of solid lattices. Less

已经开发了THZ非线性四波混合光谱仪，用于研究固体中固有的局部局部模式。由茶激光器激发的FIR激光器，由二氧化碳气体激光器激发的CW FIR激光器，一种二氧化物激光，钛sapphire激光器，傅立叶光谱仪进行了修改，转换和升级。从理论上考虑使用上述激光器的时间分辨四波混合光谱，得出的结论是，FIR激光器的频率必须与钛占钛sapphire Laser的重复频率的N谐波相吻合。必须调整钛蓝宝石激光器的空腔长度以实现这些频率的巧合。腔长的调节估计在100mm之内，并且可以进行此类长度的调整。在这项研究中，我们尚未与同步的FIR和钛式激光器（Partia）完全开发四波混合光谱仪。但是，我们一直期望该开发将完成，并测量固体的四波混合光谱。还可以预期，从非线性固有局部模式的角度来看，诸如Dietics之类的固体的相变现象将是很好的研究。基于第三阶非线性的Intrinsic局部模式在抗铁磁铁和MEMS振荡器中在实验中观察到。在这些研究中，测量四个波浪光谱和侧带共振结构的发现是非常有力的工具。在这项研究中，我们推测侧带谐振结构的起源是交叉非线性谐振频移始终大于自动非线性谐振频移。我们还推测相同的机制可以保持这种非线性本地化模式的形状。我们已经证实，基于二阶非线性的固有局部模式出现了类似的边带结构，这是实心晶格的晶格振动所期望的。较少的

项目成果

Mobile localized excitations in the acoustic spectrum of a nonlinear micromechanical cantilever array

非线性微机械悬臂阵列声谱中的移动局部激励

• 发表时间: 2007
• 期刊: Phys. Rev. Lett 98
• 作者: H. Ueba;B. N. J. Persson;M.Sato and A.J. Sievers
• 通讯作者: M.Sato and A.J. Sievers

Visualization intrinsic localized modes with a nonlinear micromechani cal array

使用非线性微机械阵列可视化固有局部模式

• 发表时间: 2008
• 期刊: Low Temperature Physics(Fizika Nizkih Temper atur) 34
• 作者: M. Sato;A. J. Sievers
• 通讯作者: A. J. Sievers

Management of localized energy in discrete nonlinear transmission lin es

离散非线性传输线中的局部能量管理

• 发表时间: 2007
• 期刊: EuroPhysics Letters 80
• 作者: M. Sato;S. Yasui;M. Kimura;T. Hikihara;A. J. Sievers
• 通讯作者: A. J. Sievers

Nonlinear Four-wave mixing Spectrometer in THz region

太赫兹区域非线性四波混频光谱仪

• 发表时间: 2008
• 作者: Seri Yamaguchi;Takako Yoshiike;Masayuki Sato
• 通讯作者: Masayuki Sato

Visualization intrinsic localized modes with anonlinear micromechanical array

非线性微机械阵列的可视化固有局部模式

• 发表时间: 2008
• 期刊: Low Temperature Physics (Fizika Nizkih Temperatur) 34
• 作者: M. Sato;A. J. Sievers
• 通讯作者: A. J. Sievers