Vacancy Waves in a Quantum Solid ィイD13ィエD1He

量子固体中的空位波

基本信息

批准号：
08240218
负责人：
MAMIYA Takayoshi
金额：
$ 44.99万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-08240218/
关键词：
Quantum Solid Spin Polaron Depressurized Solid Tunnel Effect Dislocation Zero Point Vacancy Wave Solid Helium Amorphous Solid 量子固体空格子固体ヘリウム3 量子効果固体^3He 磁気焼鈍

项目摘要

We aim at verifying that the vacancies move as vacancy waves because of tunneling of ィイD13ィエD1He atoms in solid ィイD13ィエD1He. We studied the vacancy waves in three categories. (1) specific heat, (2) motion of dislocation and (3) zero point vacancy wave. (1) A spin polaron is a region where ィイD13ィエD1He spins are aligned ferromagnetically around a vacancy. We have observed an excess specific heat over the specific heat due to the exchange interaction. We checked whether it arises from spin polarons due to vacancies by applying a strong magnetic field. The results show that the excess specific heat does not arise from spin polarons but the amorphous solid ィイD13ィエD1He layers on the substrate. (2) We studied the motion of dislocations in solid ィイD13ィエD1He by the torsional oscillator technique. We studied the temperature dependence of the critical strain amplitude where the dissipation starts to increase.We have obtained clear evidence of the crossover from thermal to quantum tunneling of the dislocations through the Peierls potential. (3) We have been performing the experiment of pulsed NMR for depressurized solid in the fields of 8-15T. We aim at observing a decrease in TィイD21ィエD2 and increases in TィイD22ィエD2 and the diffusion constant due to the appearance of zero-point vacancy waves. So far, we have not yet confirmed the presence of zero-point vacancy waves.

我们的目的是验证由于固体 D13He 中 D13D1He 原子的隧道效应，空位会以空位波的形式移动。我们研究了三类空位波：(1) 比热、(2) 位错运动和 (3) 零点空位波。 (1) 自旋极化子是 D13He 自旋铁磁排列在周围的区域。我们观察到由于交换相互作用而产生的比热过多，我们通过施加强磁场检查了其是否由空位引起。结果表明，过多的比热不是由自旋引起的。 (2) 我们通过扭转振荡器技术研究了固体 D13He 中的位错运动。耗散开始增加的临界应变幅度的温度依赖性。我们已经通过 Peierls 势获得了位错从热隧道到量子隧道交叉的明确证据 (3) 我们一直在进行减压脉冲核磁共振实验。我们的目的是观察由于零点的出现而导致的 D21D2 的减少和 D22D2 的增加以及扩散常数。到目前为止，我们还没有证实零点空位波的存在。