Design And Implement Of Low Energy Consumption Logic Device Based On Spin Torque Effects

With the technical nodes of CMOS technology goes closer to the limits of atomic scale,Moore's Law gradually fails.At the same time,with the expansion of the electronic consumer market,limited information storage capabilities are increasingly difficult to meet the requirements of infinite information storage.Under these conditions,researchers have to find new information storage technologies to achieve higher storage densities.In order to find novel,scalable and low-power computing technologies,spin-based logic devices are being widely explored due to their non-volatility,small battery area and low dynamic power consumption.So far,proposed spin logic devices include nanomagnetic logic,all-spin logic,spin torque majority gates,mLogic,spin transfer oscillator logic,and the spin wave bus devices,et al.In particular,spin logic devices are amenable to building majority gates in which the circuit complexity is largely reduced due to the device counts decrease significantly as compared to other logic styles.Here,a novel cascadable magnetic majority gate logic device has been proposed based on both spin transfer torque and spin–orbit torque effects in the MTJ.A single logic unit consists of a four MTJs and an extended free layer,which is shared by the four MTJs as their bottom FM electrode.The magnetization in free layer can be switched by spin transfer torque carried by the injected current.The output terminal locates at the joint of three input-MTJ branches,so that its magnetization can be determined by the propagation of magnetic domain walls.The NOT gate can be simply implemented through the switching of fixed layer's magnetization via SOT effect.Communication between logic units is realized by nonlocal spin diffusion current through a non-FM metal wire,which has a long enough spin diffusion length,to ensure its cascade-ability and signal nonreciprocity.Comprehensive logic functions including NAND/AND,NOR/OR,and XOR/XNOR are designed,together with the demonstration of their successful cascade-ability to implement complicated logic functions.Micromagnetic simulations are performed to evaluate the CMMG device,circuit performance,and energy consumption based on pragmatic technology.