Giant Spin Hall Effect (GSHE) Logic Design for Low Power Application
Yaojun Zhang1,a, Bonan Yan1,b, Wenqing Wu2, Hai Li1,c and Yiran Chen1,d
1Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
2Qualcomm Incorporated, San Diego, CA, USA.
Conventional CMOS transistors will reach its power wall, a huge leakage power consumption limits the performance growth when technology scales down, especially beyond 45nm technology nodes. Spin based devices are one of the alternative computing technologies that aims to replace the current MOS based circuits by taking the advantage of their attractive characteristics, including non-volatility, high integration density and small cell area. The development of technologies such as spintransfer torque random access memory (STT-RAM) and spin torque majority gate logic has become a story of great success. However, most of these technologies faces problems like, small operation margin, poor fan-out ability, etc. As the latest spin technology, Giant Spin Hall Effect (GSHE) Magnetic Tunneling Junction (MTJ) demonstrates a much better operation speed, switching probability and resistance margin. By leveraging the benefit of greater power efficiency and area density, GSHE MTJ elements become a suitable candidate for spintronic logic gates. Compare with traditional MOS transistors based logic gates, GSHE MTJ based logic can operate as a non-volatile memory and requires a much smaller number of elements to perform same logical operations (i.e., ‘AND’, ‘OR’, ‘NAND’ or ‘NOR’ gate.). And compare with other spin based logics, GSHE MTJ based logic also provides an better performance, excellent CMOS process compatibility and great fan-out ability.
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