Dynamics of Complex Systems probed through Tunneling Phenomena.

这项研究的目的是调查各种“复杂”的系统，可以通过任何可能的隧道现象，无论是旋转或位置的研究。我们最初认为的系统严格限于（1）分子相互作用是非线性的系统，（2）处于非平衡状态的系统，以及（3）涉及有序-无序性质的系统。我们的想法是，热容对获得一般方案非常敏感，原则上，非相干中子非弹性散射可以确定能量方案的细节。我们将它安装在^3He-^4He稀释制冷机中，构造了一个新的量热计系统。一种新的测量系统，还介绍了电阻电桥。这两种方法使我们能够以合理的精度测量到0.2 K的热容。为了研究这些系统的动力学性质，我们在法国格罗诺布尔的劳厄朗之万研究所和英国的拉瑟福德阿普尔顿实验室进行了中子散射实验，研究了（1）氘致相变，（2）氢键晶体中质子/氘的隧穿，（3）某些压密石英玻璃中的低能激发，（4）某些准晶体中的低能激发等。其他可能不涉及任何隧穿现象的复杂系统也在去年为该项目进行了研究。对于气固界面和固液界面上的单分子吸附膜的研究已经取得了很大的进展，我们下一步的研究工作除了从凝聚相的角度来认识外，还应该从分子水平来研究。这两种方法必须相辅相成，以实现我们的最终目标，即了解这些复杂系统的总体性质。

The aim of this research was to investigate various "complex" systems which could be studied through any possible tunneling phenomena, either rotational or positional. The systems that we originally thought were limited strictly to (1) the ones in which the molecular interactions are non-linear, (2) those being in non-equilibrium, and (3) those involving an order-disorder nature. The idea was that the heat capacity isvery sensitive to obtain the general scheme and, in principle, the incoherent neutron inelastic scattering can determine the detail of the energy scheme.A new calorimeter system has been constructed by installing it in a ^3He-^4He dilution refrigerator. A new measurement system with an a.c. resistance bridge was also introduced. They both together allowed us to measure the heat capacity down to 0.2 K with a reasonable accuracy. To investigate the dynamical aspects of the systems, neutron scattering experiments were performed at Institut Laue Langevin at Gronoble in France and at Ratherford Appleton Laboratory in Britain.The systems studied include (1) deuteration-induced phase transitions, (2) tunneling of protons/deuterons in hydrogen bonded crystals, (3) low-energy excitations in some pressure-densified silica glass, (4) low-energy excitations in some quasi-crystals, and so on. Other complex systems, which may not involve any tunneling phenomenon, were also investigated in the last year for this project. The adsorbed monolayers at gas-solid and solid-liquid interfaces have extensively been studied.In conclusion, our next move for further research would probably be to investigate the system from the molecular level in addition to the view point of recognizing the system as a condensed phase. Those two approaches must be complementary to achieve our final goal, i.e. understanding of the overall nature of those complex systems.