Magnetic dynamics were excited by microwave currents, and electric voltages along the bars were. Kent2 and hideo ohno3,4 the magnetization of a magnetic material can be reversed by using electric currents that transport spin angular momentum. The ability to reverse the magnetization of nanomagnets by current injection has attracted increased attention ever since the spin transfer. Apr 01, 2008 slonczewskis observation that a net spin current flux into a volume of magnetic material implies that a torque acts on the magnetization in that volume is the key idea for most theories of current induced torques cits. Current driven spin torque induced by the rashba effect in a ferromagnetic metal layer. We model the stfmr for all magnetization directions and in the presence of fieldlike spinorbit torques based on the driftdiffusion spin model and quantum mechanical boundary. Strong rashbaedelstein effectinduced spinorbit torques. By controlling the magnetization orientation through the interplay of magnetocrystalline. Corresponding physical mechanism is based on the spintransfer torque stt effect predicted by slonczewski and berger 1,2.
Theoretical study of current induced dynamics of an antiferromagnetic skyrmionium. For a magnetization that is misaligned from an easyaxis, a torque induces. However, in conventional sotbased heterostructures, an inplane bias magnetic field along the current direction is required for the deterministic switching. Here, we report a large sot generated by current induced spin accumulation through the rashbaedelstein effect in the composites of monolayer tmd mos 2 or. Here we explain how currents can generate torques that affect the magnetic orientation and the reciprocal effect in a wide variety of magnetic materials and structures. Theoretically, the inplane current induced spin accumulation arises from the bulk spin hall effect she of the hm layer and. The journal of magnetism and magnetic materials provides an important forum for the. The ptcopt magnetic structure is locally annealed by a laser track along the in. Pdf currentinduced spinorbit torques in ferromagnetic. Current induced switching under inplane magnetic field hx 3 oe is shown in. We also discuss recent stateoftheart demonstrations of current induced torque devices that show great promise for enhancing the functionality of semiconductor devices. Mar 02, 2021 stt and sot are simultaneously induced by a pulsed current flowing through an inplane easyaxis magnetic tunnel junction and an underneath taw channel. We report measurements of current induced torques in heterostructures of permalloy py with tate 2, a transitionmetal dichalcogenide tmd material possessing low crystal symmetry, and observe a torque component with dresselhaus symmetry.
Spin transfer torque enables current driven magnetization switching and provides a. The experimental discovery of a rashbatype torque in an fm metal at room temperature opens very promising perspectives in spintronics, namely for the fabrication of magnetic storage and logic gates operating through intrinsic currentinduced so torques. Electric field control of deterministic currentinduced magnetization. The oscillating currentinduced torque causes the py magnetization to. In the past few years, phenomena such as spin transfer torque and spinorbit. Current induced spinorbit torques sots enable efficient electrical manipulation of the magnetization in heterostructures with a perpendicular magnetic anisotropy through the rashba effect or spinhall effect. Current in the field can change by changing the position of the controls switch. Current induced spin torques on single gdfeco magnetic layers david cespedesberrocal 1,2, heloise damas 1, sebastien petitwatelot 1, david maccariello 3. Pdf currentinduced spin torques on single gdfeco magnetic. Pdf switching of perpendicular magnetization by spinorbit. Fieldfree spinorbit torque switching of perpendicular. The widely used magnetic materials, based on 3d metals such as fe and co, possess a small soc.
May 06, 2019 the switching of magnetization by current induced spinorbit torque sot has potential applications for energyefficient spintronic devices. Current induced spinorbit torques sots are of interest for fast and energyefficient manipulation of magnetic order in spintronic devices. Currentinduced spinorbit torques philosophical transactions of. However, even in a heterostructure where a metallic magnet is sandwiched by two different insulators, a nonzero spinorbit. Current induced torques in magnetic materials find, read and cite all the research you need on researchgate. Bi2se3 at room temperature can indeed apply a strong spintransfer torque to an. Strong rashbaedelstein effectinduced spinorbit torques in.
Moving a magnet towards a coil produces a timevarying magnetic field inside the coil the induced emf in a coil of n turns is equal to n times the rate of change of the magnetic flux on one loop of the coil. Using the firstprinciples quantum transport approach, we predict that injecting unpolarized charge current parallel to. Feb 15, 2021 the magnetic field of this eddy current produces a breaking force or torque in the opposite direction of rotation disc. The recently discovered twodimensional magnetic insulator cri3 is an intriguing case for basic research and spintronic applications since it is a ferromagnet in the bulk but an antiferromagnet in bilayer form, with its magnetic ordering amenable to external manipulations. May 11, 2014 magnetization switching by current induced spinorbit torques is of great interest due to its potential applications in ultralowpower memory and logic devices. Thus, there is a pressing need to employ nonmagnetic means to switch. Induced spin torques on single gdfeco magnetic layers. Aug 10, 2020 by applying current pulses and magnetic fields, we quantify the efficiency of the acting current induced torques and estimate a current field equivalence ratio of 4. Mar 22, 2021 a magnetic field exerts a force on current. In this section, we define torque and apply this concept.
Currentinduced magnetization switching through spinorbit torques is the fundamental building block of spinorbitronics, which promises highperformance, lowpower memory and logic devices. Pdf spinorbit coupling in inversionasymmetric magnetic crystals and. In this thesis, we present a theoretical study on the current induced nucleation and propagation of antiferromagnetic skyrmionium. The current induced spinorbit torque generated by spinhall source materials can be used to modulate the effective magnetic damping parameter in ferromagnets 4, 7,8. A convenient description of force associated with rotational motion is torque. Magnetic flux density relation between magnetic field intensity h and magnetic field density b measured in tesla. Pdf fieldfree spinorbit torqueinduced switching of. Piezoelectric control of the mobility of a domain wall driven. Deterministic spinorbit torque induced magnetization. Field free switching of a perpendicular magnetic tunnel junction through the interplay of spinorbit and spintransfer torques. Recent developments demonstrate that spinorbit torque sot driven magnetization switching in heavymetal hmferromagnet fm bilayer systems provides a promising writing scheme for potential applications in the magnetic memory technology. To be deterministic, however, switching of perpendicularly magnetized materials by sot requires a mechanism for inplane symmetry breaking.
Journal of magnetism and magnetic materials 320 2008 011 current perspectives currentinduced torques in magnetic metals. The spin torque ferromagnetic resonance stfmr in a bilayer system consisting of a magnetic insulator such as y 3 fe 5 o 12 and a normal metal with spinorbit interaction such as pt is addressed theoretically. The sot was first observed in a ni 81 fe 19 pt bilayer ando et al. Symmetry and magnitude of spinorbit torques in ferromagnetic.
Jan 01, 2014 we report micromagnetic simulation of spin transfer torque stt switching of a thin elliptical disc made of fullheusler co 2 feal 0. For this reason, current carrying structures in a magnetic field tend to rotate. In this work, we report on the electricfield modulation of spinorbit torques sots in. Currentinduced spinorbit torques in ferromagnetic and. Jul 01, 2019 to compare the current induced effective field in the view of current induced magnetization switching, the various h k of different devices should be considered. The optical helicityinduced torques on the magnetization, optical spin torque. In the reciprocal process a changing magnetization orientation produces currents that transport spin angular momentum. Deterministic magnetization switching by spinorbit torque. Pdf we study the current induced torques in asymmetric magnetic tunnel junctions containing a. Currentinduced torques in magnetic materials request pdf. Pdf currentinduced torques in magnetic weyl semimetal tunnel. To circumvent this shortcoming, the common practice has been to utilize the large soc of nonmagnetic layers of 5d heavy metals hms, such as pt, to generate spin currents and, in turn, exert spin torques on the magnetic layers. Sot allows the magnetization to be switched with the subns pulse down to 200 ps and stt eliminates the necessity of an external field.
However, to use 2d vdw magnets for building spintronic nanodevices such as magnetic memories, key challenges remain in terms of effectively switching the magnetization from one state to the other electrically. Spintransfer torque is the rotation that a spinpolarized current induces on the magnetization of the solid it flows through. This force is exerted in a direction perpendicular to the direction of current flow. Abinitio gmr and current induced torques in aucr multilayers p. So far, the quantitative determination of charge current induced spin current and spinorbit torques sots on the magnetic layer adjacent to twodimensional materials is still lacking.
Ralph, role of spindependent interface scattering in generating currentinduced torques in magnetic. Pdf currentinduced spinorbit torques in ferromagnetic and. Below is a recent list of 20202021 articles that have had the most social media attentio. Jan 01, 2020 the current induced torques arising from the soc, the sots, provide efficient and versatile ways to control the magnetic state and dynamics in different classes of materials. Current induced torques in magnetic materials pdf download.
Modification of spinobit torques using the ta oxidation. Nov 21, 2016 in the case of magnetic insulators mis, although charge currents cannot flow, spin currents can propagate, but current induced control of the magnetization in a mi has so far remained elusive. Calculate the magnetic field magnetic field induced at the center of a loop loop or coil coil or at the interior of a solenoid. Currentinduced torques with dresselhaus symmetry due to. Proximity spinorbit torque on a twodimensional magnet. Perspectives of electrically generated spin currents in ferromagnetic.
Current induced switching in the orientation of magnetic moments is observed in cobaltcoppercobalt sandwich structures, for currents flowing perpendicularly through the layers. In the past, most conventional works have been focused on sot in heavy metals. Then, we will discuss laserinduced torques and resultant magnetization dynamics in ferromagnetic materials. Current induced spinorbit torques mediate the transfer of angular momentum from the lattice to the spin system, leading to sustained magnetic oscillations or switching of ferromagnetic as well as. Switching of perpendicular magnetization by spinorbit.
In a direct she, an electrical current passing through a non magnetic material with. Pdf switching of perpendicular magnetization by spin. Pdf voltageinduced switching of nanoscale magnetic tunnel. The stt results in switching the direction of initial magnetization of the disc to a new state based on the spinpolarization factor. Calculate the magnetic field magnetic field induced at the center of a loop loop or coil coil or at the interior of a. Currentinduced torques in magnetic materials nature. Currentinduced spinorbit torques mediate the transfer of.
Ultrafast optical manipulation of magnetic order in ferromagnetic. We suggest that the dominant mechanism for this dresselhaus component is not a spinorbit torque but rather the oersted field arising from a component of. First, the materials and structural engineering that enhances sot efficiency are discussed. In press, journal preproof what are journal preproof articles. The rich internal degrees of freedom of magnetic domain walls make them an attractive complement to electron charge for exploring new concepts of storage, transport and processing of information. The study of spintransfer torques began in 1996 when. Current induced torques in magnetic materials arne brataas1, andrew d. The films were processed into microscale bars to perform current induced spin torque measurements. The spinorbit torques generally arise from spinorbit coupling of heavy metals. Introductionnowadays the spinpolarized current is widely used for manipulation of nano magnetic structures. Micromagnetic simulation of spin transfer torque switching of. Torque induced by a magnetic field engineering libretexts.
The magnetization of a magnetic material can be reversed by using electric currents that transport spin angular momentum. We obtained qualitatively similar results on devices with different dimensions patterned on the same fig. Current induced spinorbit torques mediate the transfer of angular momentum from. Spinorbit coupling in inversionasymmetric magnetic crystals and. Mendeley data repository is freetouse and open access.
Request pdf on jul 3, 2012, arne brataas and others published cheminform abstract. Spin and orbital properties of perpendicular magnetic. Macdonalda adepartment of physics, the university of texas at austin, austin, tx 787120264, usa. Spinorbit torques in structures with asymmetric dusting. Currentinduced torques in magnetic materials nasaads. Nov 05, 2020 current induced spinorbit torques sots in heavy metalferromagnet heterostructures have emerged as an efficient method for magnetization switching with applications in nonvolatile magnetic memory and logic devices. Current induced torques in magnetic materials pdf download torque and magnetic fields st. Macdonald1 1 department of physics, the university of texas at austin, 1 university station, austin tx 78712 2 centre for the physics of materials and department of physics, mcgill university, montreal pq, h3a 2t8, canada arxiv. Calculate the magnetic torque magnetic torque on a coil or solenoid of area a, turns n, and current i in a given bfield.
Currentinduced spinorbit torque and fieldfree switching. Current induced domain wall motion with a tagdfesin. Currentinduced magnetization switching using an electrically. This kinetic energy of rotor is converted as heat energy and dissipated from rotating disc to surrounding atmosphere. Transition metal dichalcogenides tmds have drawn great attention owing to their potential for electronic, optoelectronic, and spintronic applications. Currentinduced spinorbit torque magnetization switching. Over the past decade many experiments have confirmed,,, slonczewskis predictions. Relativistic torques induced by currents in magnetic materials. Currentinduced torques in magnetic materials nature materials. Pdf simple model of currentinduced spin torque in domain. Deterministic magnetization switching using lateral spin. Spin transfer torque is the rotation that a spinpolarized current induces on the magnetization of the solid it flows through.
In tmdsferromagnetic bilayers, an efficient spin current can be generated by the tmds to manipulate the magnetic moments in the ferromagnetic layer. Journal of magnetism and magnetic materials elsevier. A simple vision of current induced spin torque in domain walls a. Fieldfree and subns magnetization switching of magnetic. Field free magnetization reversal by spinhall effect and. Interfaceinduced fieldlike optical spin torque in a ferromagnet. Dw velocity was significantly enhanced with inplane magnetic field h inp of 25mt and velocity more than 200 ms was obtained, which was more than 25 times faster than that without magnetic field. Jan 25, 2021 we report current induced spin torques in epitaxial nimnsb films on a commercially available epiready gaas substrate. Current induced spinorbit torque magnetization switching with considering unconventional staggered spin polarization. Currentinduced spin torque resonance of magnetic insulators.
Pdf ab initio giant magnetoresistance and currentinduced. Here the sot from a ferromagnetic metal is investigated, and two mechanisms of the field free sot induced magnetization switching are demonstrated to be from the interlayer. Pt and alox layers can be switched by inplane current injection. Magnetic domains in adjacent cobalt layers can be manipulated controllably between stable parallel and antiparallel configurations by applying current pulses of the appropriate sign. Slonczewskis observation that a net spin current flux into a volume of magnetic material implies that a torque acts on the magnetization in that volume is the key idea for most theories of current induced torques cits. The nimnsb was grown by cosputtering from three targets using optimized parameters. Jan 23, 2020 current induced domain wall dw motion was observed and the dw moved along current direction without magnetic field. Verticalcurrentinduced domainwall motion in mgobased. Study of currentinduced dynamics of an antiferromagnetic.
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