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Articles you may be interested inPolarization-based all-optical logic controlled-NOT, XOR, and XNOR gates employing electro-optic effect in periodically poled lithium niobate Appl. Phys. Lett. 99, 161117 (2011) We present conceptual designs of an emerging class of logic gates, including NOT, NOR, and NAND, that use traveling spin waves ͑SWs͒ in the gigahertz range and that are based on a MachZehnder-type SW ͑MZSW͒ interferometer. In this MZSW interferometer, logical input and output signals are achievable by the application of currents in order to control the phases that are accumulated by propagating SWs and by either destructive or constructive SW interference, respectively. In this article, the operation mechanism underlying a NOT gate function using a single MZSW interferometer is described and demonstrated numerically. The MZSW interferometer can itself become a NOT gate and be combined in its parallel and serial configurations to form NAND and NOR gates, respectively, which represent emerging classes of universal logic functions for microwave information signal processing.

We found by micromagnetic simulations that the motion of a transverse wall (TW) type domain wall in magnetic thin-film nanostripes can be manipulated via interaction with spin waves (SWs) propagating through the TW. The velocity of the TW motion can be controlled by changes of the frequency and amplitude of the propagating SWs. Moreover, the TW motion is efficiently driven by specific SW frequencies that coincide with the resonant frequencies of the local modes existing inside the TW structure. The use of propagating SWs, whose frequencies are tuned to those of the intrinsic TW modes, is an alternative approach for controlling TW motion in nanostripes.

The magnetic vortex with in-plane curling magnetization and out-of-plane magnetization at the core is a unique ground state in nanoscale magnetic elements. This kind of magnetic vortex can be used, through its downward or upward core orientation, as a memory unit for information storage, and thus, controllable core switching deserves some special attention. Our analytical and micromagnetic calculations reveal that the origin of vortex core reversal is a gyrotropic field. This field is induced by vortex dynamic motion and is proportional to the velocity of the moving vortex. Our calculations elucidate the physical origin of the vortex core dynamic reversal, and, thereby, offer a key to effective manipulation of the vortex core orientation. DOI: 10.1103/PhysRevLett.100.027203 PACS numbers: 75.40.Gb, 75.40.Mg, 75.60.Jk, 75.75.+a Vortex patterns exist in physical dynamic systems of greatly varying temporal and spatial scales, ranging from quantized vortices in superfluids and superconductors [1] to water whirlpools, atmospheric tornadoes, and galaxies of the universe. These patterns reveal generic similarities such as the circular (spiral) structure of some parameters (density, velocity, etc.) and a vortex core. Intervortex forces and vortex inertial force (mass) are also somewhat similar in different vortex systems, because the vortices can often be treated as particles (solitons). The governing equations usually are nonlinear. Magnetic vortices are among the most prominent examples of the magnetization (M) ground states typically observed in submicron magnetic particles, such as nanodots [2 -4]. Control of the M reversal in small particles is on the cutting edge of modern nanomagnetism. Vortices are elementary objects that describe the M reversal in such particles via their nucleation, propagation, and annihilation [5]. The magnetic vortex consists of the core (VC), a small area of 10 -20 nm radius R c wherein M deviates from the dot plane [2,3], and the main part with the in-plane curling M around its core area. All known vortices are topological solitons or topological ''defects'' described by circulation, winding number, vorticity, etc. Magnetic vortices have topological charges of two different types [6], vorticity q and polarization p, whereas other vortices usually have only one type. Existence of the VC nonzero topological charges [1,6] in combination with the long-range magnetostatic interaction leads to unique effects in vortex dynamics. Nontrivial vortex excitations emerge that exist neither in bulk magnetic systems nor in continuous films. The vortex in nanodots possesses, in particular, a dynamic excitation, corresponding to the rotation of its core around an equilibrium position at a characteristic frequency of several hundred MHz [7][8][9][10][11][12][13]. The gyroforce responsible for this excitation, being perpendicular to the vortex velocity, is formally similar to the Magnus force acting on vortices in hydro-(aero-) dynamics, superfluids, and superconductors, but is of different physical orig...