Cryogenic memory architecture integrating spin hall effect. This book offers detailed insights into spin transfer torque stt based devices, circuits and memories. Description this firstofitskind resource is completely dedicated to spin transfer torque stt based devices, circuits, and memory. A great interest is now given for the spintransfer torque stt switching approach which requires a lower current e. The alignment of the magnetization of a nano magnet. In addition, it offers cmos compatible architectures with highspeed read and write operations.
The anomalous hall effect in ferromagnets is a wellknown phenomenon in which electromotive force is generated in the direction perpendicular to both the electric current and the magnetization. Spintransfer torque induced by the spin anomalous hall effect. We present a nandlike spintronics memory nand spin device for highdensity nonvolatile memory applications. Switching based spin transfer torque oscillator with zero. These devices are part of the itrs exploratory road map. The physics and dependency of tmr on mtj processing parameters can be found in19. A prime application of mtjs is in building nonvolatile look up tables lut used in recon. Spin transfer torque magnetic randomaccess memory sttram or sttmram is a nonvolatile memory with nearzero leakage power consumption which is a major advantage over charge based memories such as sram and dram. Remarkable progress in stt switching with mgo mtjs and increasing interest in sttmram in semiconductor industry have been witnessed in recent years. Spinorbittorquebased devices, circuits and architectures. Fast simulation of spin transfer torque devices in a general. Learn more mram is attracting a lot of attention as an embedded memory for asics and mcus, but issues of write current and data retention have caused concern. Logicin memory applications are already in the development stage. Spin transfer torque can be used to flip the active elements in magnetic randomaccess memory.
Therefore, a technological assessment on sttram is crucial, especially when the technology is not commercially available. A physically unclonable function puf with a spin device spin transfer torque magnetoresistive random access memory, sttmram is presented. This spin accumulation in the fl exerts a torque on fl that favors the orientation opposite to the pl magnetization. We also provide researchers an insight into the future potentials of the sot based designs. We give an overview of cmoscompatible spintronics applications. Us9577641b2 spin transfer torque based memory elements for. Jan 14, 2020 cryogenic memory architecture integrating spin hall effect based magnetic memory and superconductive cryotron devices. Selfsustained spin transfer torque devices based braininspired processor powered by energy harvesting technology for internet of things applications human brains are vastly more energy efficient at interpreting the world visually or understanding speech than any cmos based computer system of the same size. A comparative study between spintransfertorque and spin. In such a case, the current is spin polarized in a pinned magnet and the polarized spin is used to switch a free magnet. Among the diverse applications of spintronics, security for internetofthings iot devices is one of the most important. Exploring spintransfertorque devices and memristors for.
Spintransfer torque magnetic memory as a stochastic memristive. These drawbacks prevent fimsmrams further development in memory and logic circuit. Spin memory is developing spintransfer torque stt mram technologies and products that can replace sram static ram and ultimately dram dynamic ram in both embedded and standalone applications. Graphene is an ideal channel material in this context due to its long spin diffusion length, gatetunable. This paper will discuss the current state of research into spin transfer torque random access memory sttram, a type of spintronic device that shows promise as a scalable memory technology. One class of such devices is allspin logic asl which is based on switching ferromagnets by spin transfer torque and conduction of spinpolarized current. Spinorbittorquebased devices, circuits and architectures arxiv.
Switching based spin transfer torque oscillator with zerobias field and large tuningratio gaurav gupta1,2, zhifeng zhu2 and gengchiau liang2 1spin devices, delhi 16, india 2department of electrical and computer engineering, national university of singapore, singapore 117576. Fast erasing and programming of magnetic tunnel junction mtj are implemented with two unidirectional currents generating spin orbit torque sot and spin transfer torque stt, respectively. Devices based on such autooscillations called spin torque oscillators stos 11 can be used as tunable sources of microwave radiation 12, spin wave generators and amplifiers for. Dubbed spintransfer torque stt mram, it promises speed and reliability comparable to that of static randomaccess memory, or sramthe quickaccess memory embedded inside microprocessors. Starting with the basic concepts and device physics, it then addresses advanced stt applications and discusses the outlook for this cuttingedge technology. Starting with the basic concepts and device physics, it then addresses advanced stt. A comparative study between spintransfertorque stt and spinhalleffect she switching mechanisms in pmtj using spice ibrahim ahmed, zhengyang zhao, meghna g. Computing in memory with spintransfer torque magnetic ram. This firstofitskind resource is completely dedicated to spin transfer torque stt based devices, circuits, and memory. Nanomagnonic devices based on the spintransfer torque.
To solve for the spin transfer torque acting on a static magnetic configuration, the consensus view is that one should determine the spin current density q through an analysis of the spin dependent electron transport in the device structure, and then identify the torque from the divergences of q near magnetic interfaces or in regions of non. Spin transfer torque stt based devices, circuits, and memory by and shivam vermabrajesh kumar kaushik and shivam verma topics. The spin transfer torque magnetoresistive random access memory sttmram is the leading candidate for spin based memories. One of the most promising candidates for nvram technology is the spin transfer torque ram spram based on magnetic tunnel junction mtj device technology. The demand for lowpower and highperformance integrated circuits ics has been increasing as artificial intelligence ai and internetofthings iot. A comparative study between spintransfertorque stt and spin.
Already, spin memory has developed breakthrough technologies in both magnetics and cmos circuits and architectures that bring sttmram to the next generation. Spin transfer torque magnetic tunnel junction sttmtjbased. Spin transfer, torque based logic devices that use spins and magnets for information processing have been proposed. The alignment of the magnetization of a nanomagnet. A wide range of topics including, stt mrams, mtj based logic circuits, simulation and modeling strategies, fabrication of mtj cmos circuits, nonvolatile computing with stt mrams, all spin logic, and spin information processing are explored. Design of an erasable spintronics memory based on current. Reliability analysis of spin transfer torque based look up. The device resistance depends on the orientation of mtj magnetization mz with ferromagnetic. Request pdf spin transfer torque stt based devices, circuits, and memory this firstofitskind resource is completely dedicated to spin transfer torque. Magnetic tunnel junction mtj based spin transfer torque magnetic random. Benchmarking of beyondcmos exploratory devices for logic. Spintransfer torque magnetic random access memory sttmram or sotmrams 14 and magnetic sensors for sensing magnetic fields in the range of picotesla 5, to more emerging technologies such as neuromorphic 6 and nonboolean computing 7, 8, interconnects 9 and logic implementations 10. While several fieldfree spin orbit torque sotdriven logic devices. Spin transfer torque stt switching demonstrated in submicron sized magnetic tunnel junctions mtjs has stimulated considerable interest for developments of stt switched magnetic random access memory sttmram.
Spin transfer torque stt switching realized using a magnetic tunnel junction mtj device has shown great potential for low power and nonvolatile storage. Due to their nonvolatility and high density, spin transfer torque stt devices. The exploitation of the spin transfer torque effect for cmos compatible computing 97 a universal memory that squares the circle of simultaneously being fast, nonvolatile, small in size, allows high integration density, and is cmos compatible is spin transfer. The spin hall effect she based mram is an alternative for the sttmram, which also provides nonvolatility, zero leakage, and competitive area per bit. Spin transfer torque based devices, circuits, and memory. Request pdf nanomagnonic devices based on the spintransfer torque magnonics is based on signal transmission and processing by spin waves or their quanta, called magnons propagating in a. The exploitation of the spintransfer torque effect for cmos. Mechanism and assessment of spin transfer torque stt based. Spintransfer torque magnetic memory sttmram has gained significant research interest due to its nonvolatility and zero standby. First, we present a brief introduction to the physical background considering such effects as magnetoresistance, spin transfer torque stt, spin hall effect, and magnetoelectric effects. To this end, we have added simulation capabilities for stt devices to.
The stt spin transfer torque has emerged as a promising memory technology to provide energy efficient, nonvolatile, high density memories with low power dissipation and unlimited endurance. Spin transfer torque stt based mram is then evaluated to address these issues, some design techniques and novel computing architecture for fpga logic circuits based on sttmram technology are presented in this article. Such luts use a hybrid integration of cmos transistors and mtj devices. Spin transfer torque random access memory sttram is a type of nonvolatile rams that is typically used for more conventional memory circuits, such as, cache, secondary storage etc. One of the most promising candidates for nvram technology is the spintransfer torque ram spram based on magnetic tunnel junction mtj device technology. Among them, spin transfer torque magnetic ram sttmram is one of the most promising candidates for constructing the nextgeneration lowpower and highdensity nonvolatile memory.
Nevertheless, the high write energy and read disturbance of the sttmram motivated researchers to find other solutions. Spin transfer torque stt based devices, circuits, and memory. Ieee transactions on biomedical circuits and systems, institute of electrical and electronics. As interest in spin based devices and especially spin transfer torque stt based memory is growing, it appears essential to provide simulation support for these novel devices not just through special purpose tools, but inside a general purpose tcad device simulator. Current highspeed highdensity logic circuits like fpgascplas typically do not employ sttram or other stt based elements. A recent progress of spintronics devices for integrated. Spin transfer torque in a graphene lateral spin valve. Nonvolatile spin logic devices to enable scaling are being extensively studied. Spin transfer torqueram devices as a future nonvolatile.
A number of spin device ideas propose using spin current to carry information coherently through a spin channel and transfering it to an output magnet by spin transfer torque. Spintransfer torque magnetic memory sttmram has gained significant research interest due to its nonvolatility and zero standby leakage, near unlimited endurance, excellent integration density, acceptable read and write performance, and compatibility with cmos process technology. Spin transfer torque random access memory emerging. Spin memory s 3dmlc technologies are the basis of the companys future products for magnetic dram and storageclass memory replacement. Longterm reliable physically unclonable function based on. Oxide tunnel barrier breakdown is used to realize longterm stability for pufs. A comparative study between spintransfertorque stt and. Thus, if the starting configuration is parallel and the spin accumulation is large enough, it can force the magnetization direction of the fl. Spin transfer torque magnetic random access memory sttmram or sot mrams 14 and magnetic sensors for sensing magnetic. Exploring spin transfer torque devices and memristors for logic and memory applications. Kaushik roy as scaling cmos devices is approaching its physical limits, researchers have begun exploring newer devices and architectures to replace cmos. Spintransfer torque can be used to flip the active elements in magnetic randomaccess memory.