Relationship between symmetry and scaling of spin torque thermal switching barrier

Abstract

This letter shows that the scaling relationship between the thermal reversal barrier and the (spin polarized) current density in the limit of low current density strongly depends on magnetization dynamics symmetry. This is quite different from magnetic field induced thermal switching. Our analysis demonstrates that the widely used scaling relationship between switching time and current density needs to be modified to include magnetization dynamics symmetry effects. A formula for a thermal reversal barrier symmetry correction factor is given in the limit of low current density. The implications for the estimation of magnetic element thermal stability are discussed.