Wide operating window spin-torque majority gate towards large-scale integration of logic circuits

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.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 f...

[1]  Dmitri E. Nikonov,et al.  Cascade-able spin torque logic gates with input–output isolation , 2015 .

[2]  Plamen Stamenov,et al.  Spin-orbit torque switching without an external field using interlayer exchange coupling. , 2016, Nature nanotechnology.

[3]  Iuliana Radu,et al.  Toward error-free scaled spin torque majority gates , 2016 .

[4]  Eric E. Fullerton,et al.  Domain wall motion in nanopillar spin-valves with perpendicular anisotropy driven by spin-transfer torques , 2012 .

[5]  Rudy Lauwereins,et al.  Wave pipelining for majority-based beyond-CMOS technologies , 2017, Design, Automation & Test in Europe Conference & Exhibition (DATE), 2017.

[6]  D Petit,et al.  Magnetic Domain-Wall Logic , 2005, Science.

[7]  Y Suzuki,et al.  Micromagnetic understanding of current-driven domain wall motion in patterned nanowires , 2005 .

[8]  T. Ghani,et al.  Proposal of a Spin Torque Majority Gate Logic , 2010, IEEE Electron Device Letters.

[9]  Hideo Ohno,et al.  Spatial control of magnetic anisotropy for current induced domain wall injection in perpendicularly magnetized CoFeB|MgO nanostructures , 2012 .

[10]  L. Pileggi,et al.  Novel STT-MTJ Device Enabling All-Metallic Logic Circuits , 2012, IEEE Transactions on Magnetics.

[11]  Iuliana Radu,et al.  Operating conditions and stability of spin torque majority gates: Analytical understanding and numerical evidence , 2017 .

[12]  G. Beach,et al.  Nonlinear domain-wall velocity enhancement by spin-polarized electric current. , 2006, Physical review letters.

[13]  Giovanni De Micheli,et al.  Majority-Inverter Graph: A New Paradigm for Logic Optimization , 2016, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems.

[14]  B. Leven,et al.  Design of a spin-wave majority gate employing mode selection , 2014, 1408.3235.

[15]  Wolfgang Porod,et al.  Majority logic gate for 3D magnetic computing. , 2014, Nanotechnology.

[16]  Kang L. Wang,et al.  Switching of perpendicular magnetization by spin-orbit torques in the absence of external magnetic fields. , 2013, Nature nanotechnology.

[17]  Rudy Lauwereins,et al.  Exchange-driven Magnetic Logic , 2017, Scientific Reports.

[18]  W. Porod,et al.  Shape Engineering for Controlled Switching With Nanomagnet Logic , 2012, IEEE Transactions on Nanotechnology.

[19]  R. Cowburn,et al.  Room temperature magnetic quantum cellular automata , 2000, Science.

[20]  Mathias Kläui,et al.  Current-induced domain wall motion in nanoscale ferromagnetic elements , 2011 .

[21]  James A. Hutchby,et al.  Limits to binary logic switch scaling - a gedanken model , 2003, Proc. IEEE.

[22]  G. Csaba,et al.  Majority Gate for Nanomagnetic Logic With Perpendicular Magnetic Anisotropy , 2012, IEEE Transactions on Magnetics.

[23]  Rudy Lauwereins,et al.  Non-volatile spin wave majority gate at the nanoscale , 2016, ArXiv.

[24]  G.A. Jullien,et al.  A method of majority logic reduction for quantum cellular automata , 2004, IEEE Transactions on Nanotechnology.

[25]  Tahir Ghani,et al.  Nanomagnetic circuits with spin torque majority gates , 2011, 2011 11th IEEE International Conference on Nanotechnology.

[26]  S. Sarma,et al.  Spintronics: Fundamentals and applications , 2004, cond-mat/0405528.

[27]  Dmitri E. Nikonov,et al.  Switching efficiency improvement in spin torque majority gates , 2014 .

[28]  Rudy Lauwereins,et al.  Inverter Propagation and Fan-Out Constraints for Beyond-CMOS Majority-Based Technologies , 2017, 2017 IEEE Computer Society Annual Symposium on VLSI (ISVLSI).

[29]  C. Ross,et al.  Low Energy Magnetic Domain Wall Logic in Short, Narrow, Ferromagnetic Wires , 2012, IEEE Magnetics Letters.

[30]  K. Omari,et al.  Chirality-Based Vortex Domain-Wall Logic Gates , 2014 .