Discrete resistance fluctuations in pressure-type point contacts

In high ohmic pressure-type metallic point contacts (resistance range 50 Ω to 3 k Ω) the point-contact resistance is observed to switch randomly between two or more discrete levels. This effect can be explained by the motion or reorientation of single defects, thereby changing their cross section for electron scattering. From the temperature- and voltage-dependence of the characteristic times of the fluctuations, electromigration parameters for a defect in silver are extracted.