Magnetic device comprising: - a first magnetic layer, known as storage layer, having a uniaxial anisotropy with an easy magnetisation axis in the plane of said storage layer and having a magnetisation of variable direction having two positions of equilibrium along said easy magnetisation axis; - a second magnetic layer, known as electron spin polarisation layer, having a magnetisation perpendicular to that of said storage layer and situated out of plane of the electron spin polarisation layer; - means for making circulate in the layers, and perpendicularly thereto, a current pulse to switch from one position of equilibrium of the direction of magnetisation of the storage layer to the other; - means for applying a magnetic field, known as transverse field, the direction of which is substantially parallel to the plane of said storage layer and substantially perpendicular to the easy magnetisation axis of the storage layer; said device being characterised in that - said means for making a current pulse circulate and said means for applying a transverse magnetic field are configured such that the scalar product the sign "x" designating the vectorial product, is of the same sign as the component of the magnetisation of the polarisation layer along an axis going from the polarisation layer to the storage layer, where represents the initial magnetisation vector in one of the two positions of equilibrium of the storage layer, represents the current density vector to switch the magnetisation of the storage layer from the initial state corresponding to the position of equilibrium before switching to the final state corresponding to the second state of equilibrium after switching and represents the vector of the transverse field, - the amplitude of the writing current pulse and that of the transverse magnetic field are chosen to switch the magnetisation of the storage layer from one position of equilibrium to another position of equilibrium, the final state of the magnetisation of the storage 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. - a first magnetic layer, known as storage layer, having a uniaxial anisotropy with an easy magnetisation axis in the plane of said storage layer and having a magnetisation of variable direction having two positions of equilibrium along said easy magnetisation axis; - a second magnetic layer, known as electron spin polarisation layer, having a magnetisation perpendicular to that of said storage layer and situated out of plane of the electron spin polarisation layer; - means for making circulate in the layers, and perpendicularly thereto, a current pulse to switch from one position of equilibrium of the direction of magnetisation of the storage layer to the other; - means for applying a magnetic field, known as transverse field, the direction of which is substantially parallel to the plane of said storage layer and substantially perpendicular to the easy magnetisation axis of the storage layer; - said means for making a current pulse circulate and said means for applying a transverse magnetic field are configured such that the scalar product the sign "x" designating the vectorial product, is of the same sign as the component of the magnetisation of the polarisation layer along an axis going from the polarisation layer to the storage layer, where represents the initial magnetisation vector in one of the two positions of equilibrium of the storage layer, represents the current density vector to switch the magnetisation of the storage layer from the initial state corresponding to the position of equilibrium before switching to the final state corresponding to the second state of equilibrium after switching and represents the vector of the transverse field, - the amplitude of the writing current pulse and that of the transverse magnetic field are chosen to switch the magnetisation of the storage layer from one position of equilibrium to another position of equilibrium, the final state of the magnetisation of the storage 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.