Ballistic bit addressing in a magnetic memory cell array

Abstract

A ringing free bit addressing scheme for magnetic memories like MRAM (magnetic random access memory) is proposed. As in standard MRAM addressing schemes the switching of a selected cell is obtained by the combination of two half-select field pulses. Numerical solutions of a single spin model of an MRAM cell show that the pulse parameters can be chosen such that the application of the half select pulse induces a full precessional turn of the magnetization (no switch) whereas the superposition of two half select pulses induces a half precessional turn (switch). With well adapted pulse parameters both fullselect and half-select switching occurs on ballistic trajectories characterized by the absence of ringing after magnetic pulse decay. Such ballistic bit addressing allows ultra high MRAM clock rates. 1