Negative magnetoresistance in the nearest-neighbor hopping conduction
Physics Department, The Hong Kong University of Science and Technology Clear Water Bay, Hong Kong
2 Department of Physics, Oklahoma State University - Stillwater, OK 74078, USA
Accepted: 20 February 1997
We propose a size effect which leads to the negative magnetoresistance in granular metal-insulator materials in which the hopping between two nearest-neighbor clusters is the main transport mechanism. We show that the hopping probability increases with magnetic field. This is originated from the level crossing in a few-electron cluster. Thus, the overlap of electronic states of two neighboring clusters increases, and negative magnetoresistance results.
PACS: 72.20.My – Galvanomagnetic and other magnetotransport effects / 73.50.Jt – Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects) / 71.55.Jv – Disordered structures; amorphous and glassy solids
© EDP Sciences, 1997