2018/02/07 by Yin Zhang, H. Y. Yuan, X. S. Wang +1 · 33 citations
Engineering · Mathematics · Physics and Astronomy · #Advanced Memory and Neural Computing #Bottleneck #Computer science #Condensed matter physics #Current (fluid) #Current density #Limit (mathematics) #Magnetic field #Magnetic properties of thin films #Magnetoresistive random-access memory #Mathematical analysis #Mathematics #Orbit (dynamics) #Order (exchange) #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Random access memory #Spin (aerodynamics) #Torque #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.97.144416
published in Physical review. B./Physical review. B 97(14) (American Physical Society)
arxiv created 2018/02/07 · openalex created_date 2018/02/23 · openalex publication_date 2018/04/20 · arxiv updated 2018/04/25 · openalex updated_date 2026/08/05
Spin-orbit-torque magnetic random access memory (SOT-MRAM) is a promising technology for the next generation of data storage devices. The main bottleneck of this technology is the high reversal current density threshold. This outstanding problem is now solved by a new strategy in which the magnitude of the driven current density is fixed while the current direction varies with time. The theoretical limit of minimal reversal current density is only a fraction (the Gilbert damping coefficient) of the threshold current density of the conventional strategy. The Euler-Lagrange equation for the fastest magnetization reversal path and the optimal current pulse is derived for an arbitrary magnetic cell and arbitrary spin-orbit torque. The theoretical limit of minimal reversal current density and current density for a GHz switching rate of the new reversal strategy for CoFeB/Ta SOT-MRAMs are, respectively, of the order of 105 A/cm2 and 106 A/cm2 far below 107 A/cm2 and 108 A/cm2 in the conventional strategy. Furthermore, no external magnetic field is needed for a deterministic reversal in the new strategy.