Spin Torque Efficiency and Analytic Error Rate Estimates of Skyrmion Racetrack Memory

摘要

In this paper the critical currents as well as the thermal stability ofskyrmion racetrack like structures is investigated. It is reported that thepinning sites which are required in order to allow for thermally stable bitssignificantly increases the critical current densities to about $j_{crit}$ =0.62 TA/m$^2$ to move the bits in skyrmion like structures. By calculating thethermal stability as well as the critical current we can derive the spin torqueefficiency wich is $eta$ = $Delta/I_c = 0.19 k_BT_{300}~mu$ A which is insimilar range of simulated spin torque efficiency of MRAM structures. . Finallyit is shown that the stochastic depinning process of any racetrack like devicerequire very narrow switching or depinning time distribution in order to avoidthermally written in errors or special current profiles allowing for a clockcycle.