A magnetoresistive sensor including: a first pinned-magnetization magnetic layer, called pinned layer; a free-magnetization magnetic layer, called sensitive layer, of which the magnetization, in the absence of an external field, is substantially orthogonal to the magnetization of the pinned layer, the pinned and sensitive layers being separated by a first separating layer for magnetic uncoupling; and a layer, called lateral coupling layer, located on the side of the sensitive layer opposite that of the separating layer, the lateral coupling layer serving to control the lateral spin transfer.