Noise properties of the spin-valve transistor

Noise measurements have been performed on a spin-valve transistor. This tra nsistor consists of a Pt/NiFe/Au/Co/Au multilayer sandwiched between two se miconductors. For comparison, we also studied metal base transistors with a Pt/Au or Pt/NiFe/Au base. All samples show full shot noise in the collecto r current. The inclusion of a spin-valve in the base layer decreases the ab solute value of the collector current and with it the noise level but it do es not change the nature of the noise in this device. Similarly, the collec tor current, and therefore, the noise changes as a function of magnetic fie ld for the spin-valve transistor, but no additional noise of magnetic origi n is observed. (C) 2001 Elsevier Science B.V. All rights reserved.