Oscillatory Striction and Electron-Lattice Interaction

金属化合物的弹性常数在低温下随外加电场的量子振荡称为声德哈斯效应。这是测定导电电子系统中电子-晶格相互作用的一个很好的探针，这与超导的BCS机制有关。Goto用3He低温恒温器和稀释制冷机建立了低温下声学德哈斯效应的实验方法。金属化合物的样品长度在低温下也表现出量子振荡。这被称为振荡磁致伸缩，它也起源于费米表面上的电子-晶格相互作用。在本研究项目中，我们通过超声速度和磁致伸缩研究了声德哈斯效应。在电容桥电容测量的基础上，研制了振荡磁致伸缩仪。由于电容电桥在很小的输入功率下提供了理想的证明，因此电容电桥在低温测量中表现优异。此外，电容桥的高分辨率可以精确测量与电子-晶格耦合有关的振荡强度。在这个项目中，我们开发了电容电池，它可以沿着超导磁体内部的外加磁场控制样品的取向。在本项目中，我们制作了3He低温恒温器的磁致伸缩装置，但更复杂的稀释制冷机系统仍有待开发。本项目重点研究了稀土单晶、CeBi、LaBi、LaAs和铀化合物USb等低载流子化合物的声de Haas效应。对铈铋中重孔表面β 4的观察为体系中p-f的混合机制提供了证据。声学de Haas效应对LaAs和LaBi的振荡强度表明，低载流子化合物中含有体积应变的纵向声波的电子-晶格相互作用显著增强。这是研究低载流子体系中电子相关的一个重要结果。少

The quantum oscillation of the elastic constant of metallic compounds at low temperature as a function of applied field is called as the acoustic de Haas effect. This is an excellent probe to determine the electron-lattice interaction of the conduction electron system, which is related to the BCS mechanism of superconductivity. Goto has established the experimental method of the acoustic de Haas effect at low temperatures by 3He cryostat and dilution refrigerator. The sample length of metallic compounds also showes the quantum oscillation at low temperatures. This is called as the oscillatory magneto-striction, which is also originated from the electron-lattice interaction on the Fermi surface. In the present research project we have studied the acoustic de Haas effect by the ultrasonic velocity as well as the magneto-striction. We have done a development of the apparatuse for the oscillatory magneto-striction based on the capacitance measrement with a capacitance bridge. The capacitan … More ce method is excellent for the low temperature measurements because the capacitance bridge provides an ideal prove with quite small input power. Furthermore the highly resolution of capacitance bridge leads an accurate measurement of the oscillatory intensity which is related to the electron-lattice coupling. In this project we developed the capacitance cell, which may control sample orientation along applied magnetic fields inside the superconducting magnet. In the present project we made the magneto-striction apparatus for the 3He cryostat, but more sophisticated system for the dilution refrigerator is still remained to be developed.The investigation of the acoustic de Haas effect on the low carrier compounds on rare earth monopnictides, CeBi, LaBi, LaAs and uranium compound USb were performed intensively in this project. The observation of the heavy hole surface beta4 in Ce Bi gave an evidence for the p-f mixing mechanism in the system. The oscillation intensity of the acoustic de Haas effect on LaAs and LaBi shows that the electron-lattice interaction of the longitudinal sound wave containing the volume strain in low carrier compounds is enhanced considerably. This is an very important result relating to the electron correlation in the low carrier system. Less