High Frequency Oscillation due to Tunneling of Charged Particles

点击翻译按钮获取中文摘要

In the present research, we constructed the following apparatuses:1. An apparatus for the construction of contactless tunnel junction with a very small junction area and a small junction capacitance. This apparatus is similar to a scanning tunneling microscope (STM).2. A vacuum system with a facility to make surfaces of junction electrodes clean.3. A low-temperature apparatus of contactless tunnel junction.Using contactless tunnel junction in air, we obtained the following results:1. Tunneling current between thin metal film and scanning tip becomes unstable because electric charge accumulates at grains of thin metal film.2. We measured STM images of fine noble metal particles supported on the oxidized titanium plate. We found that fine metal particles gather together and move to the direction perpendicular to the scanning direction of tip because of electrostatic force induced by electric charge accumulated on fine metal particles.3. Tunnel junction between a metal whisker and a scanning tip has a very small capacitance. Top of a metal whisker is sharper than that of the scanning tip.