Patent ID: 8098105

Claim:
A radio-frequency oscillator comprising a magnetoresistive device in which an electric current is able to flow, said magnetoresistive device comprises: a first magnetic layer, known as “trapped layer”, whereof the magnetization is of fixed direction; a second magnetic layer known as “free layer”; a non-magnetic insulating matrix interposed between the first and second layers, the non-magnetic layer being electrically non-conductive; and a soluble metal electrode being at least partially dissolved in the insulating matrix either by photodissolution (UV) or by heat treatment, the soluble metal being one of (i) a separately applied soluble electrode layer and (ii) a portion of the trapped layer, wherein the oscillator further comprises means capable of causing an electron current to flow in said layers constituting the magnetoresistive device and in a direction perpendicular to the plane which contains said layers; wherein the magnetoresistive device further comprises at least one constriction zone of the electric current passing through the magnetoresistive device, wherein the at least one constriction zone is constituted by a nano-path or nano-wire extending through the insulating matrix and said soluble metal electrode dissolved therein, and wherein the nano-path or nano-wire results from the subjection of the insulating matrix to a voltage suitable for generating the nano-path or nano-wire.