A novel non-volatile flip-flop based on spin-orbit torque magnetic tunnel junctions (SOT-MTJ) is proposed for fast and ultra-low energy applications. A case study of this nonvolatile flip-flop is considered. In addition to the independence between writing and reading paths which offers a high reliability, the low resistive writing path performs high speed and energyefficient write operation. We compare the SOT-MTJ performances metrics with the spin transfer torque (STT-MTJ). Based on accurate compact models, simulation results show an improvement which attains 20× in terms of write energy per bit cell. At the same writing current and supply voltage, the SOT-MTJ achieves a writing frequency 4× higher than the STT-MTJ.

Magnetic random access memory based on magnetic tunnel junctions (MTJs) is among the most attractive technologies of emerging nonvolatile memories. However, the integration of spin-based devices in integrated circuits is still hindered by a lack of established standard electrical simulator models. Many of such models have been proposed during the past decade which can be classified into two categories: the first ones are based on the physical Landau-Lifshitz-Gilbert (LLG) equation describing real-time MTJ magnetic switching dynamics; the second one uses analytical expressions for switching thresholds derived from the LLG equation. The aim of this reported work was to investigate for the first time the capability of each strategy to fulfil the need of industrial standard electrical simulation tools and pave the path towards a standard industrial model. Multi-simulator compatibility, efficient runtime, accuracy and reliability are the three main assets of a device model. It is shown that using the Cadence ® tools suite with the Spectre ® simulator, the LLG modelling strategy overcomes the analytical approach in terms of accuracy and speed with a 7× faster runtime. Both models require nearly the same hardware memory resources.