Brain-Inspired Computing with Spin Torque Devices

In this paper we discuss the potential of emerging spintorque devices for computing applications. Recent proposals for spin-based computing schemes may be differentiated as 'all-spin' vs. hybrid, programmable vs. fixed, and, Boolean vs. non-Boolean. All-spin logic-styles may offer high area-density due to small form-factor of nano-magnetic devices. However, circuit and system-level design techniques need to be explored that leaverage the specific spin-device characterisitcs to achieve energy-efficiency, performance and reliability comparable to those of CMOS. The non-volatility of nano-magnets can be exploited in the design of energy and area-efficient programmable logic. In such logic-styles, spin-devices may play the dual-role of computing as well as memory-elements that provide field-programmability. Spin-based threshold logic design is presented as an example. Emerging spintronic phenomena may lead to ultra-low-voltage, current-mode, spin-torque switches that can offer attractive computing capabilities, beyond digital switches. Such devices may be suitable for non-Boolean data-processing applications which involve analog processing. Integration of such spin-torque devices with charge-based devices like CMOS and resistive memory can lead to highly energy-efficient information processing hardware for applicatons like pattern-matching, neuromorphic-computing, image-processing and data-conversion. Finally, we discuss the possibility of using coupled spin-torque nano oscillators for low-power non-Boolean computing.