A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Interestingly, skyrmion size is only weakly tdependent and does not. The focus of this nirt is synthesis of new nanoscale magnetic molecules, whose magnetic and electrical properties can be tailored by design, and development of techniques to assemble these molecular magnets and more conventional electronic and magnetic materials together to create new nanostructures and nanostructured magnetic materials. For lithographically patterned magnetic structures, magnetically soft disk is very unique, as the magnetic vortex is usually energetically stable 11. Magnetic nanostructures is the first and only reference source ever published to bring together all aspects of magnetic nanostructures for a wide range of readers. Paoflow is a software tool to efficiently postprocess standard first principles electronic structure planewave pseudopotential calculations in order to promptly compute from interpolated band structures and density of states several quantities that provide insight on transport, optical, magnetic and topological properties such as anomalous and spin hall conductivity ahc and. The plane magnetic nanostructures for the study of the spin transfer effect frank joseph albert, ph. Written to berkeleygw wfn, rho, vxc and vkb files but no longer used except in sapo code in berkeleygw. The new feature of our setup is floquet engineering of interactions using time dependent zeeman shifts, that can be realized either using state dependent optical stark shifts or magnetic fields. The magnetic heterostructure is patterned into a nanopillar sandwiched between a cu lower lead and a au upper lead to allow vertical spin transport through the structure. Berkeleygw is a massively parallel computational package for electron excitedstate properties that is based on the manybody perturbation theory employing the ab initio gw and gw plus bethesalpeter equation methodology. The properties of the resulting kondo model strongly depend on the anisotropy of the ferromagnetic interactions. A dissertation submitted to the faculty of the graduate school of the university of minnesota by xi chen in partial fulfillment of the requirements for the degree of doctor of philosophy randall h. The evolution of skyrmions in irfecopt multilayers and their.
Cornell university 2007 in this thesis, i have employed point contact spectroscopy to determine the nature of electron transport across constrained domain walls in a ferromagnetic nanocon. Topological hall effect and berry phase in magnetic nanostructures. Buy spin dependent transport in magnetic nanostructures advances in condensed matter science on free shipping on qualified orders. Applicationscan be found in, for example, recording media, magnetoresistive sensors, read heads, and magnetic random access memory. Magnetic nanostructures in ultrahighdensity data storage will be of interest to r and d scientists in both. Elsevier journal of magnetism and magnetic materials 156 1996 315316 invited paper iii journal of magnetism and magnetic materials spin dependent transport in magnetic nanostructures s. Second harmonic detection of spin dependent transport in magnetic nanostructures article pdf available in chinese physics letters 272 february 2010 with 39 reads how we measure reads. Manufacture, physics, devices, and modeling, march 9, 2008 department of physics, new york university andrew d. In the scenario of the ringshaped magnetization state, the stray field of the nanoring vanishes in zero magnetic field since, if compared to the nanodisk, the perpendicular vortex is no longer present. Spin current, spin accumulation and spin hall effect. Spin dependent transport in magnetic nanostructures advances. Transition to the quantum hall regime in inas nanowire. Apr 18, 2014 the paper presents magnetic and transport properties of compositionally modulated feal multilayer structures mls, with an overall atomic concentration ratio of fe. The crucial role of these structures in nanotechnology is brought out by considering some of their unique aspect ratio dependent properties.
Spintransport and transfer in magnetic nanostructures. The magnetic nanostructures should have commercial applications in magnetic hard disks for computer information storage, magnetic sensors, spin valves, magnetic tunnel junctions, highspeed nonvolatile magnetic random access memories mrams, magnetic imaging, magnetic recording heads, magnetoelectronics, magnetooptics and other spintronic. Spin current, spin accumulation and spin hall effect ncbi. With gmr, the resistance of a magnetic multilayer is affected by the relative orientation of its magnetic layers due to electron spin dependent scattering. This volume, written by a team of foremost experts, addresses the exciting and rapidly developing topic of ultrahighdensity magnetic data storage. The study presented in this thesis is concerned with the spin dependent transport and spin transfer in magnetic nanostructures. Spin dependent transport and spin transfer in nanoconstrictions and current confined nanomagnets ozhan ozatay, ph. Pdf magnetic materials have become controllable on the nanometre scale. We have shown that the magnetic behavior of permalloy nanostructures is governed by the shape. Magnetic nanostructures 1 emil burzo magnetic nanostructures. Quantum transport in noncollinear magnetic nanostructures. In a device containing a superconductor f1sf2, the e. Spin dependent transport in magnetic nanostructures crc press.
It combines modern topics in nanomagnetism with issues relating to the fabrication and characterization of magnetic nanostructures. This resource letter provides a guide to the literature in the still rapidly developing area of spin dependent transport phenomena, which forms the basis for applications in magnetoelectronics. Dont set to different values in different files for the same system or you will get errors in berkeleygw. Spindependent transport phenomena in magnetic nanostructures. Instead, the magnetic moment will precess at different frequencies at different location governed by its local field 9,10. Topological properties and dynamics of magnetic skyrmions.
Here, using density functional theory dft calculations, we investigate the spin dependent electronic transport across vdw magnetic tunnel junctions mtjs composed of fe3gete2 ferromagnetic electrodes and a graphene or hexagonal boron nitride hbn spacer layer. The second edition now contains greater coverage of the quantum hall effect, in. Spin injection and nonlocal spin transport in magnetic. Spin transport in magnetic nanostructures how is spin transport in magnetic nanostructures abbreviated. It is shown that, only in the nanostructures with symmetric magnetic field with respect to the magnetic modulation direction, electrons exhibit a considerable. They then describe quantum confined systems, transmission in nanostructures, quantum dots and single electron phenomena. In summary, these are some cluster like nanostructures. Asymmetry in time evolution of magnetization in magnetic.
The first two chapters are dedicated to introduce spin electronics, electrical transport and the experimental techniques commonly used in this work. Spindependent tunneling in nanostructures consisting of. Transport in nanostructures second edition providing a muchneeded update on the latest experimental research, this new edition has been thoroughly revised and develops a detailed theoretical framework for understanding the behavior of mesoscopic devices. Magnetic nanostructures have a number of potential applications, of which some are being commercialized already. Spin transport and current induced magnetization dynamics in. Here, using halltransport and magneticimaging in a technologically. Thermally activated reversal in magnetic nanostructures ulrich nowak theoretische physik, gerhardmercatoruniversitat duisburg 47048 duisburg, germany abstract the miniaturization of magnetic structures plays an important role for fundamental research as well as for technical applications. Magnetic nanostructures are nanostructures which contain at least one magnetic constituent. Traditional approaches to using spin are base on the alignment of a spin relative to a reference, for example an external magnetic eld. Spindependent transport in magnetic nanostructures is based on the physics of the interaction between spin and charge. Request pdf spin dependent transport in antiferro and ferrimagnetic nanostructures spin transfer torque stt and tunnelling magnetoresistance tmr in magnetic tunnel junctions with. Separate chapters are devoted to interference in diffusive transport and temperature decay of fluctuations, and the book concludes with a chapter on nonequilibrium transport and nanodevices. A nanostructure is an object of intermediate size between molecular and microscopic micrometersized structures in describing nanostructures it is necessary to differentiate between the number.
In this sense, the spincharge separation of electrons is a starting point for the physics of spinelectronics. The magnetic vortex in soft magnetic nanoscale disks nanodots consists of a well known arrangement of magnetic dipoles that form a swirl in the plane of the disk with a small outofplane singularity in the center called a vortex core 7. University of groningen spin caloritronics in magneticnon. The phenomena also depend on the geometry of the devices. Lifshitzgilbert equation by a nutation term allows us to study the signi. An important focus of the group focus lies in the investigation of the electronic and magnetic properties of nanostructures at surfaces. We describe electrical detection of spin pumping in metallic nanostructures. The interesting aspect of magnetic nanostructures is the fact that two ferromagnetic fm layers with a. User guide qespresso internet forum 64 bit computing. Study of thicknessdependent magnetic and transport. Spin transport in magnetic nanostructures listed as stmn. Spin transport and transfer basics giant magnetoresistance gmr spin filtering and spin momentum transfer ii.
Fabrication and characterization of magnetic nanostructures. Our group studies theoretically the electronic properties of nanostructure materials containing planes, lines or clusters of magnetic materials. Electrical detection of spin pumping physics of quantum devices. Cornell university 2012 this dissertation describes a number of research projects with the common. Regarding magnetism transition metal and rareearth atoms, metaloxydes etc. The fieldinduced impact on magnetic nanostructures with a large spin orbit interaction, consisting in magnetization reversal under ultrashort circularly polarized laser pulses or unipolar electric field pulses are studied. Doping dependence of transport properties in fe1xcoxsi. Cornell university 2003 this dissertation describes the development and use of a set of techniques used to fabricate magnetic nanostructures where a current can be applied perpendicular to the plane of the thin.
Characterization of spin transfer torque and magnetization manipulation in magnetic nanostructures chen wang, ph. All mls show soft ferromagnetic behaviour at room temperature rt with an in plane easy axis of magnetization. I have been trying to calculate the band gap and the density of states of the graphene flake system using quantum espresso, and it is actually unstable to the size of the supercell. Spin transport in magnetic nanostructures how is spin. Regarding magnetic anisotropy, this will play an important role in. Spin transport and current induced magnetization dynamics in magnetic nanostructures. Spin dependent transport in magnetic nanostructures. Spindependent transport phenomena in magnetic nanostructures are of.
Size and orientation of magnetic moments and magnetization depend in general sensitively on atomic environment, atomic coordination surfaces, interfaces etc. Spindependent transport in magnetic nanostructures. Some of their technical applications are presented. In each case, coercivity increases continuously and magnetization decreases with an. Since the discovery of giant magnetoresistance gmr in these superlattices in 1988, spin dependent transport phenomena in magnetic nanostructures have. Typical systems are layered st ructures with ferromagnetic and nonmagnetic layers or arrays of ferromagnetic dots on a nonmagnetic substrate. Spindependent transport in antiferro and ferrimagnetic. We study the spin dependent transport properties of the nanostructures consisting of realistic magnetic barriers produced by the deposition of ferromagnetic stripes on heterostructures. In recent years it has become possible to manipulate atomic planes, lines of atoms, small clusters or even individual atoms to create new manmade materials nanostructures engineered on an atomic scale. Spin relaxation from continuous film to magnetic nanostructures. Institute for theoretical physics events xwrcaldesc. Sahakyan the state engineering university of armenia, yerevan, armenia. The sense of the dipole curl defines the vortex chirality and the direction of the dipole moment in the.
A dramatic increase in research activities on nanostructured magnetic materials and their based industrial applications has created a great demand for a reference source in this area. Using stateoftheart commercial and homemade density functional theory and kinetic monte carlo codes software we study, among other things, electronic properties of nanoscale surface structures, and spin dependent effects therein, to better understand. He has recently served on the aip steering cmte for magnetic materials, and as a committee member. An external file that holds a picture, illustration, etc. Spintransport and transfer basics giant magnetoresistance gmr spin filtering and spin momentum transfer ii. Special attention is paid to the spin accumulation and spin current caused by spin injection into non magnetic metals and semiconductors and superconductors. It can be used in conjunction with many densityfunctional theory codes for groundstate properties, including paratec, parsec, quantum espresso, siesta, and octopus. Inoue department of applied physics, nagoya unirersity. Magnetic nanostructures for lateral spintransport devices. The dependence of magnetic spin and orbital moments and spin correlations on particle size and temperature are of interest. Warnings on bad preprocessing option when compiling iotk should also be ignored. For the stt effect, a spin polarized electric current is used to alter the magnetic state of a ferromagnet.
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