Neutron scattering from tunneling protons in metals

✍ Scribed by J. Kondo

• Book ID: 103890947
• Publisher: Elsevier Science
• Year: 1986
• Weight: 525 KB
• Volume: 141
• Category: Article
• ISSN: 0378-4363
• DOI: 10.1016/0378-4363(86)90256-1

✦ Synopsis

We consider a two-level system in metals, in which a proton is tunneling between two neighbouring sites. Cross section of inelastic neutron scattering from this system is calculated. The interaction with the metallic electrons reduces the level separation and causes a level broadening. The ratio of the former to the latter turns out to increase as a negative power of the temperature as the temperature decreases. Thus, the proton may make a coherent motion at very low temperatures. 'Ihe cross-over temperature where this ratio goes through unity is shown to be of the order of the level separation at T = 0. This result explains a recent neutron experiment on the proton in niobium with a small amount of oxygen.