Abstract
Spin Torque Majority Gate (STMG) is a logic concept that inherits the non-volatility and the compact size of MRAM devices. In the original STMG design, the operating range was restricted to very small size and anisotropy, due to the exchange-driven character of domain expansion. Here, we propose an improved STMG concept where the domain wall is driven with current. Thus, input switching and domain wall propagation are decoupled, leading to higher energy efficiency and allowing greater technological optimization. To ensure majority operation, pinning sites are introduced. We observe through micromagnetic simulations that the new structure works for all input combinations, regardless of the initial state. Contrary to the original concept, the working condition is only given by threshold and depinning currents. Moreover, cascading is now possible over long distances and fan-out is demonstrated. Therefore, this improved STMG concept is ready to build complete Boolean circuits in absence of external magnetic fields.
Highlights
As scaling of Metal-Oxide-Semiconductor field effect transistors is approaching fundamental limits,[1] the low power and non-volatility provided by spintronics[2] could be utilized in a new logic paradigm
The Spin Torque Majority Gate (STMG) concept has been explored through micromagnetic simulations[16,17] but was shown to have a narrow operating region,[18,19] requiring either very low effective anisotropy or very small Magnetic Tunnel Junctions (MTJs)
As shown in Refs. 18 and 19, for standard MTJ sizes, when the domain wall reaches the center of the cross, it is already too far from the inputs to be pushed by exchange
Summary
As scaling of Metal-Oxide-Semiconductor field effect transistors is approaching fundamental limits,[1] the low power and non-volatility provided by spintronics[2] could be utilized in a new logic paradigm. Spin-Torque Majority Gate (STMG)[16] uses spin manipulation in a continuous spintronic bus to enable high density and low power It takes advantage of the inherent non-volatility of the ferromagnetic layer and benefits from the stack development of Magnetic Random Access memories. The STMG concept has been explored through micromagnetic simulations[16,17] but was shown to have a narrow operating region,[18,19] requiring either very low effective anisotropy or very small Magnetic Tunnel Junctions (MTJs). The combination of these two criteria leads to limited non-volatility and challenging device fabrication.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
