Abstract
This paper proposes a novel logic device (SkyLogic) based on skyrmions that are magnetic vortex-like structures having low depinning current density and are robust to defects. A charge current sent through a polarizer ferromagnet (P-FM) nucleates a skyrmion at the input end of an intragate FM interconnect with perpendicular magnetic anisotropy (PMA-FM). The output end of the PMA-FM forms the free layer of an magnetic tunnel junction (MTJ) stack. A spin Hall metal (SHM) is placed beneath the PMA-FM. The skyrmion is propagated to the output end of the PMA-FM by passing a charge current through the SHM. The resistance of the MTJ stack is low (high) when a skyrmion is present (absent) in the free layer, thereby realizing an inverter. A framework is developed to analyze the performance of the SkyLogic device. A circuit-level technique is developed that counters the transverse displacement of skyrmion in the PMA-FM and allows the use of high current densities for the fast propagation. The design space exploration of the PMA-FM material parameters is performed to obtain an optimal design point. At the optimal point, we obtain an inverter delay of 434 ps with a switching energy of 7.1 fJ.
Original language | English (US) |
---|---|
Article number | 8660572 |
Pages (from-to) | 1990-1996 |
Number of pages | 7 |
Journal | IEEE Transactions on Electron Devices |
Volume | 66 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2019 |
Bibliographical note
Publisher Copyright:© 2019 IEEE.
Keywords
- Design space exploration
- skyrmions
- spintronics