Investigation of Thermal Effects in Small Structures

9501108 Wybourne电子的相位记忆在尺寸小于 电子-电子和电子-声子相互作用长度。 在这种情况下，样品中没有耗散，并且经典电流路径之外的部分阻尼影响与电子相位相关的传输现象。 在拟议的研究中，一个相关的运输制度，其中样品尺寸大于电子-电子相互作用长度，但小于电子-声子弛豫长度，将进行研究。 在这种情况下，相位记忆丢失，但样本内的耗散仍然不太可能。 为了研究耗散与样品几何形状之间的关系，将在不同条件下对不同形状的金属微结构进行电子输运测量。 远 从平衡。 当电子-声子驰豫长度接近样品尺寸时，预计电子能量损失会出现波动。 预计样品中的耗散取决于结构中的声模限制，特别是当限制的声模能量间隔大于电子气的内能时。 许多实验已经报道了相位相干性和弹道电子输运的能量耗散主要发生在电路接触。 当与能量损失相关的特征长度变为 与样品尺寸相当。 在拟议的研究中， 电子传输测量将是 制成 在远离平衡的条件下，以研究能量耗散和微观结构的几何形状之间的关系。 耗散和微结构的声学性能之间的连接也将被调查。 ***

9501108 Wybourne The phase memory of electrons is maintained in samples with dimensions less than the electron-electron and electron-phonon interaction lengths. In this situation there is no dissipation in the sample, and parts of the sdample outside the classical current path influence transport phenomena associated with the electron's phase. In the proposed research, a related transport regime in which the sample dimensions are greater than the electron-electron interaction length, but less than the electron-phonon relaxation length, will be studied. In this case phase memory is lost, yet dissipation within the sample remains unlikely. To study the relationship between dissipation and sample geometry, electron transport measurements will be made on metal microstructures of different shapes under conditions far from equilibrium. Fluctuations in the electron energy loss are anticipated when the electron-phonon relaxation length approaches the sample dimensions. Dissipation in the sample is expected to be dependent on the acoustic mode confinement in the structure, especially when the confined acoustic mode energy spacing is greater than the internal energy of the electron gas. %%% Many experiments have been reported on phase coherence and ballistic electron transport for which energy dissipation occurs mainly in the circuit contacts. Little experimental work has been directed towards the onset of dissipation in microstructures (as in computer chips) that occurs when the characteristic length associated with energy loss becomes comparable to the sample dimensions. In the proposed research, electron transport measurements will be made under conditions far from equilibrium in order to study the relationship between energy dissipation and the geometry of a microstructure. The connection between dissipation and the acoustic properties of the microstructures will also be inve stigated. ***