The Experts below are selected from a list of 79824 Experts worldwide ranked by ideXlab platform
Russell P. Cowburn - One of the best experts on this subject based on the ideXlab platform.
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4 Magnetic Domain Wall Logic
Nanotechnology, 2010Co-Authors: D A Allwood, Russell P. CowburnAbstract:Magnetic Domain Wall logic technology is based upon controlling the magnetization processes in ferromagnetic nanowire circuits. Opposite magnetization directions in the nanowires are used to denote logical “1” and “0”. Switching between these two states is achieved by using applied magnetic fields to propagate magnetic Domain Walls through the nanowires. Nanowire junctions are used to perform various operations, including logical NOT, logical AND, signal fan-out and signal cross-over. A suitable combination of these structures in a digital circuit allows any computation to be performed. Data writing and erasing can also achieved by using additional circuit features and control of the applied magnetic field. To illustrate the potential use of magnetic Domain Wall logic, a shift register with continuous data recirculation is presented. Finally, the future potential of this nascent technology is discussed, with particular emphasis on non-volatile serial data storage. Keywords: magnetic logic; Domain Walls; nanotechnology; magnetic nanostructures; magnetic nanowires; digital circuits
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VHDL simulation of Magnetic Domain Wall Logic
2006Co-Authors: Jacques-olivier Klein, D Petit, Russell P. Cowburn, Claude Chappert, Eric Belhaire, Dan ReadAbstract:The VHDL simulation of Domain Wall logic allows to validate magnetic circuits functionality early in the design stage. In this paper, we present two VHDL simulation techniques for Domain Wall logic. The first one, closer to the physics, uses models of components described at the behavioral level. It allows to study the basic functions and reveals the specificities of DW logic. The second one, closer to the logic, models components with logic gates and delays and it allows very fast simulation of complex circuits.
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Magnetic Domain-Wall logic
Science, 2005Co-Authors: D A Allwood, G. Xiong, C C Faulkner, D Petit, D Atkinson, Russell P. CowburnAbstract:"Spintronics," in which both the spin and charge of electrons are used for logic and memory operations, promises an alternate route to traditional semiconductor electronics. A complete logic architecture can be constructed, which uses planar magnetic wires that are less than a micrometer in width. Logical NOT, logical AND, signal fan-out, and signal cross-over elements each have a simple geometric design, and they can be integrated together into one circuit. An additional element for data input allows information to be written to Domain-Wall logic circuits.
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magnetic Domain Wall dynamics in a submicrometre ferromagnetic structure
Nature Materials, 2003Co-Authors: D Atkinson, C C Faulkner, D A Allwood, Gang Xiong, M D Cooke, Russell P. CowburnAbstract:As fabrication technology pushes the dimensions of ferromagnetic structures into the nanoscale, understanding the magnetization processes of these structures is of fundamental interest, and key to future applications in hard disk drives, magnetic random access memory and other 'spintronic' devices1,2,3,4. Measurements on elongated magnetic nanostructures5,6 highlighted the importance of nucleation and propagation of a magnetic boundary, or Domain Wall, between opposing magnetic Domains in the magnetization reversal process. Domain-Wall propagation in confined structures is of basic interest7,8 and critical to the performance of a recently demonstrated magnetic logic scheme for spintronics9. A previous study of a 500-nm-wide NiFe structure obtained very low Domain-Wall mobility in a three-layer device10. Here we report room-temperature measurements of the propagation velocity of a Domain Wall in a single-layer planar Ni80Fe20 ferromagnetic nanowire 200 nm wide. The Wall velocities are extremely high and, importantly, the intrinsic Wall mobility is close to that in continuous films11, indicating that lateral confinement does not significantly affect the gyromagnetic spin damping parameter to the extreme extent previously suggested10. Consequently the prospects for high-speed Domain-Wall motion in future nanoscale spintronic devices are excellent.
Hans Jurgen Richter - One of the best experts on this subject based on the ideXlab platform.
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Domain Wall assisted magnetic recording
Applied Physics Letters, 2006Co-Authors: Yu A Dobin, Hans Jurgen RichterAbstract:Using numerical and analytical micromagnetics the authors calculated the switching fields and energy barriers of the composite (exchange spring) magnetic recording media, which consist of layers with high and low magnetocrystalline anisotropies. The authors demonstrate that the ultimate potential of the composite media is realized if the interfacial Domain Wall fits inside the layers. The switching occurs via Domain Wall nucleation, compression in the applied field, depinning, and propagation through the hard/soft interface. The authors demonstrate that the Domain Wall assisted magnetic recording offers up to a threefold areal density gain over conventional single layer recording.
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Domain Wall assisted magnetic recording
arXiv: Materials Science, 2006Co-Authors: Yu A Dobin, Hans Jurgen RichterAbstract:Using numerical and analytical micromagnetics we calculated the switching fields and energy barriers of the composite (exchange spring) magnetic recording media, which consist of layers with high and low magnetocrystalline anisotropy. We demonstrate that the ultimate potential of the composite media is realized if the interfacial Domain Wall fits inside the layers. The switching occurs via Domain Wall nucleation, compression in the applied field, de-pinning and propagation through the hard/soft interface. This Domain Wall assisted switching results in a significant reduction of the switching field without substantial decrease of the for thermal activation energy barrier. We demonstrate that the Domain Wall Assisted Magnetic Recording (DWAMR) offers up to a three-fold areal density gain over conventional single layer recording.
D Atkinson - One of the best experts on this subject based on the ideXlab platform.
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controlling Domain Wall pinning in planar nanowires by selecting Domain Wall type and its application in a memory concept
Applied Physics Letters, 2008Co-Authors: D Atkinson, David S Eastwood, Lara K. BogartAbstract:Here, we report on the control of Domain Wall pinning at notch features patterned in Permalloy planar nanowires by selecting the micromagnetic configuration of the Domain Wall using a transverse magnetic field. The Domain Wall behavior was investigated both experimentally using focused magneto-optic Kerr effect measurements of lithographically patterned nanowires and with micromagnetic simulations. The pinning behavior observed is utilized in a concept for multibit memory cells applicable as the free layer in magnetic random access memory where the Domain structure is defined by the location of Domain Walls that either pin or passby pinning structures depending upon the Domain Wall configuration selected.
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Magnetic Domain-Wall logic
Science, 2005Co-Authors: D A Allwood, G. Xiong, C C Faulkner, D Petit, D Atkinson, Russell P. CowburnAbstract:"Spintronics," in which both the spin and charge of electrons are used for logic and memory operations, promises an alternate route to traditional semiconductor electronics. A complete logic architecture can be constructed, which uses planar magnetic wires that are less than a micrometer in width. Logical NOT, logical AND, signal fan-out, and signal cross-over elements each have a simple geometric design, and they can be integrated together into one circuit. An additional element for data input allows information to be written to Domain-Wall logic circuits.
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magnetic Domain Wall dynamics in a submicrometre ferromagnetic structure
Nature Materials, 2003Co-Authors: D Atkinson, C C Faulkner, D A Allwood, Gang Xiong, M D Cooke, Russell P. CowburnAbstract:As fabrication technology pushes the dimensions of ferromagnetic structures into the nanoscale, understanding the magnetization processes of these structures is of fundamental interest, and key to future applications in hard disk drives, magnetic random access memory and other 'spintronic' devices1,2,3,4. Measurements on elongated magnetic nanostructures5,6 highlighted the importance of nucleation and propagation of a magnetic boundary, or Domain Wall, between opposing magnetic Domains in the magnetization reversal process. Domain-Wall propagation in confined structures is of basic interest7,8 and critical to the performance of a recently demonstrated magnetic logic scheme for spintronics9. A previous study of a 500-nm-wide NiFe structure obtained very low Domain-Wall mobility in a three-layer device10. Here we report room-temperature measurements of the propagation velocity of a Domain Wall in a single-layer planar Ni80Fe20 ferromagnetic nanowire 200 nm wide. The Wall velocities are extremely high and, importantly, the intrinsic Wall mobility is close to that in continuous films11, indicating that lateral confinement does not significantly affect the gyromagnetic spin damping parameter to the extreme extent previously suggested10. Consequently the prospects for high-speed Domain-Wall motion in future nanoscale spintronic devices are excellent.
Lara K. Bogart - One of the best experts on this subject based on the ideXlab platform.
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Dependence of Domain Wall pinning potential landscapes on Domain Wall chirality and pinning site geometry in planar nanowires
Physical Review B, 2009Co-Authors: Lara K. Bogart, Del Atkinson, K. J. O'shea, Damien Mcgrouther, Stephen McvitieAbstract:We report on Domain Wall pinning behavior and the potential-energy landscapes created by notches of two different geometries in planar Permalloy nanowires. Domain Wall depinning was probed experimentally using spatially resolved magneto-optical Kerr effect measurements. The spin structure of pinned Domain Walls was determined using Lorentz microscopy, and Domain Wall pinning behavior was also analyzed using micromagnetic simulations, which are in good qualitative agreement with experimental results. All notch structures have dimensions that are comparable with the Domain Wall length scales. For the notch structures investigated, the depinning field experienced by a Domain Wall is found to be relatively insensitive to notch geometry although the pinning behavior is highly sensitive to both the Wall type and the Wall chirality spin structure. Energetically, the notches present both potential barriers and/or potential wells depending on the micromagnetic structure of the Domain Wall, and we find that the chirality of the Domain Wall is a key determinant of the pinning potential landscape. The pinning behavior of Domain Walls is discussed in detail, and direct quantitative measurements of the width and depth of the potential wells and/or barriers responsible for Domain Wall pinning are given for vortex Walls pinned in triangular and rectangular notches.
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controlling Domain Wall pinning in planar nanowires by selecting Domain Wall type and its application in a memory concept
Applied Physics Letters, 2008Co-Authors: D Atkinson, David S Eastwood, Lara K. BogartAbstract:Here, we report on the control of Domain Wall pinning at notch features patterned in Permalloy planar nanowires by selecting the micromagnetic configuration of the Domain Wall using a transverse magnetic field. The Domain Wall behavior was investigated both experimentally using focused magneto-optic Kerr effect measurements of lithographically patterned nanowires and with micromagnetic simulations. The pinning behavior observed is utilized in a concept for multibit memory cells applicable as the free layer in magnetic random access memory where the Domain structure is defined by the location of Domain Walls that either pin or passby pinning structures depending upon the Domain Wall configuration selected.
Yu A Dobin - One of the best experts on this subject based on the ideXlab platform.
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Domain Wall assisted magnetic recording
Applied Physics Letters, 2006Co-Authors: Yu A Dobin, Hans Jurgen RichterAbstract:Using numerical and analytical micromagnetics the authors calculated the switching fields and energy barriers of the composite (exchange spring) magnetic recording media, which consist of layers with high and low magnetocrystalline anisotropies. The authors demonstrate that the ultimate potential of the composite media is realized if the interfacial Domain Wall fits inside the layers. The switching occurs via Domain Wall nucleation, compression in the applied field, depinning, and propagation through the hard/soft interface. The authors demonstrate that the Domain Wall assisted magnetic recording offers up to a threefold areal density gain over conventional single layer recording.
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Domain Wall assisted magnetic recording
arXiv: Materials Science, 2006Co-Authors: Yu A Dobin, Hans Jurgen RichterAbstract:Using numerical and analytical micromagnetics we calculated the switching fields and energy barriers of the composite (exchange spring) magnetic recording media, which consist of layers with high and low magnetocrystalline anisotropy. We demonstrate that the ultimate potential of the composite media is realized if the interfacial Domain Wall fits inside the layers. The switching occurs via Domain Wall nucleation, compression in the applied field, de-pinning and propagation through the hard/soft interface. This Domain Wall assisted switching results in a significant reduction of the switching field without substantial decrease of the for thermal activation energy barrier. We demonstrate that the Domain Wall Assisted Magnetic Recording (DWAMR) offers up to a three-fold areal density gain over conventional single layer recording.
