MAGNETIC DEVICE WITH SPIN POLARISATION

摘要

A magnetic device includes a first magnetic layer, known as storage layer, having a uniaxial anisotropy with an easy magnetisation axis in the plane of the storage layer and having a magnetisation of variable direction having two positions of equilibrium along the easy magnetisation axis, a second magnetic layer, known as electron spin polarisation layer, having a magnetisation perpendicular to that of the storage layer and situated out of plane of the electron spin polarisation layer, a device configured to make circulate in the layers, and perpendicularly thereto, a current to switch from one position of equilibrium of the direction of magnetisation of the storage layer to the other. The device further includes a device to apply a magnetic field, known as transverse field, the direction of which is substantially parallel to the plane of the storage layer and substantially perpendicular to the easy magnetisation axis of the storage layer.

主权项

1. A magnetic device comprising:
a first magnetic layer having a uniaxial anisotropy with an easy magnetisation axis in a plane of said first magnetic layer and having a magnetisation of variable direction having two positions of equilibrium along said easy magnetisation axis; a second magnetic layer having a magnetisation perpendicular to that of said first magnetic layer and situated out of plane of the second magnetic layer; a device configured to make circulate in the layers, and perpendicularly thereto, a current pulse to switch from one position of equilibrium of the direction of magnetisation of the first magnetic layer to the other, and a device configured to apply a transverse magnetic field, a direction of which is substantially parallel to the plane of said first magnetic layer and substantially perpendicular to the easy magnetisation axis of the first magnetic layer, wherein said device configured to make a current pulse circulate and said device configured to apply a transverse magnetic field are configured such that a scalar product ({hacek over (J)}×{hacek over (M)}initial).{hacek over (H)}y, the sign “×” designating the vectorial product, is of the same sign as a component of the magnetisation of the second magnetic layer along an axis going from the second magnetic layer to the first magnetic layer, where {hacek over (M)}initial represents an initial magnetisation vector in one of the two positions of equilibrium of the first magnetic layer, {hacek over (M)} represents a current density vector to switch the magnetisation of the first magnetic layer from the initial state {hacek over (M)}initial corresponding to the position of equilibrium before switching to a final state corresponding to the second state of equilibrium after switching and {hacek over (H)}y represents the vector of the transverse field, and wherein the amplitude of the writing current pulse and that of the transverse magnetic field are chosen to switch the magnetisation of the first magnetic layer from one position of equilibrium to another position of equilibrium, the final state of the magnetisation of the first magnetic layer being controlled by the direction of the current pulse passing through the stack, independently of its initial state and the duration of the writing current pulse.