One-dimentional magnonic crystal as a medium with magnetically tunable disorder on a periodical lattice

We show that periodic magnetic nanostructures (magnonic crystals) represent an ideal system for studying excitations on disordered periodical lattices because of the possibility of controlled variation of the degree of disorder by varying the applied magnetic field. Ferromagnetic resonance (FMR) data collected inside minor hysteresis loops for a periodic array of Permalloy nanowires of alternating width and magnetic force microscopy images of the array taken after running each of these loops were used to establish convincing evidence that there is a strong correlation between the type of FMR response and the degree of disorder of the magnetic ground state. We found two types of dynamic responses: anti-ferromagnetic (AFM) and ferromagnetic (FM), which represent collective spin wave modes or collective magnonic states. Depending on the history of sample magnetization either AFM or FM state is either the fundamental FMR mode or represents a state of a magnetic defect on the artificial crystal. A fundamental state can be transformed into a defect one and vice versa by controlled magnetization of the sample.Comment: 4 pages, 3 figures, Letter paper, already submitted to PR

Continuous Interpolation of Solution Sets of Lipschitzian Quantum Stochastic Differential Inclusions

Given any finite set of trajectories of a Lipschitzian quantum stochastic differential inclusion (QSDI), there exists a continuous selection from the complex-valued multifunction associated with the solution set of the inclusion, interpolating the matrix elements of the given trajectories. Furthermore, the difference of any two of such solutions is bounded in the seminorm of the locally convex space of solutions

INFLUENCE OF CAPACITY BUILDING TRAINING BY AGRICULTURAL MEDIA RESOURCES AND EXTENSION CENTRE (AMREC) ON RURAL FARMERS’ LIVELIHOODS IN ODEDA LOCAL GOVERNMENT AREA OF OGUN STATE

The role of extension service providers as practical problem-solving organizations in rural settings is targeted at poverty reduction, various mechanisms including capacity building training is adopted in achieving this. Purposive selection of hundred and twelve (112) beneficiaries from 14 communities was made. The mean age of respondents is 39years. The household size is 6persons and the farm size is 2.3hectares. Farming experience is 8years and the average yield is 184.6kg, average annual income after the training is N15, 732.00k. 62.5% and 37.5% of farmers respectively benefitted from crop and livestock training and also have access to hybrid stems and seeds.  Results indicates positive relationship between farm size (r = 0.397, p = 0.001), farm yield (r = 0.555, p = 0.004) and farmers income (r = 0.808, p = 0.002), farmers’ sex, (χ2 =10.63, df = 1, P > 0.05) and the purpose of attending the training (χ2 =11.67, df = 4, P > 0.05). The mean score of farmers’ response on perception about the benefits of capacity building training on their livelihoods is 3.66. 95.5% and 80.4% strongly agreed that the training has assisted in poverty reduction and that it is a developmental issue targeted at building human resources.     &nbsp

Tunable 2-D magnonic crystals: effect of packing density

Magnonic crystals, periodic arrays of magnetic structures, have emerged as a promising platform for manipulating and controlling spin waves in magnetic materials. Magnetic antidot nanostructures, representing 2-D magnonic crystals, are versatile platforms for controlling and manipulating magnons. In this work, we systematically investigate the effects of inter-hole spacing and lattice (rhombic and honeycomb) arrangements on the dynamic properties of Ni80Fe20 antidot structures. The dynamic responses of antidot lattices of fixed hole diameter (d = 280 nm) and inter-hole spacing (s) between 90 and 345 nm are investigated using broadband ferromagnetic spectroscopy. Multiple resonance modes sensitive to s are observed due to the inhomogeneous internal field distribution induced by the presence of holes. There is a marked variation in mode frequency, mode intensity and the number of modes for rhombic antidot lattice as the inter-hole spacing and applied field direction are varied. Our experimental results are in good agreement with micromagnetic simulations. Our findings may find application in the design of magnonic-based devices