Differential Spin Hall Effect-Based Nonvolatile Static Random Access Memory for Energy-Efficient and Fast Data Restoration Application

Abstract

Spintronics, being a burgeoning area of research, aims to incorporate magnetic tunnel junction (MTJ), as a basic storage building block, to various electronic applications. In continuation of many device structure using MTJ such as spin-transfer torque (STT)-MTJ, spin Hall effect (SHE)-MTJ, spin–orbit torque (SOT)-MTJ, domain wall-based MTJ, and complementary polarizer MTJ, this paper presents a differential spin Hall effect (DSHE). The working and operational analysis of the DSHE-based memory element is presented. It provides 50% improved write energy and more than 1.5 times faster read as compared to a single-ended SHE-MTJ. The device structure is well suited for various differential circuit applications, for example, nonvolatile static random access memory (NVSRAM), nonvolatile flip flop (NVFF), magnetic full adder, and nonvolatile differential sense latch, with a fast and energy-efficient operation. In addition, DSHE-MTJ application for NVSRAM (named as DSNVM) is proposed. Performance of DSNVM is compared with the STT+SHE-based NVSRAM (named as SHENVM). DSNVM shows improved performance in terms of area overhead, restoration delay, and energy. DSNVM provides 40% faster restoration and 16.7% lesser energy as compared to SHENVM. Furthermore, a computational investigation for cell stability is depicted using butterfly curve and N-curve methods. Usually, write noise margins deteriorate in NVSRAMs due to the constituent NV cell. However, read as well as write noise margin is improved in DSNVM.