Figure 1: Experimental dynamic magnonic crystal (DMC) system.
From: All-linear time reversal by a dynamic artificial crystal
(a) The DMC comprises a planar current-carrying meander structure with 20 periods of lattice constant a=300 μm (10 shown), positioned close to the surface of an Yttrium Iron Garnet thin-film spin-wave waveguide (thickness 5 μm, width 2 mm). Two spin-wave antennae are arranged on the surface of the film 8 mm apart: one to launch a spin-wave signal, amplitude AS(t) and to detect the signal AR(t) reflected by the DMC, and a second to detect the signal AT(t) transmitted through it. (b) Theoretical spin-wave dispersion relationship for the waveguide with no applied current (dotted, light blue) and with a static current of 1 A in the meander structure (solid curve, dark blue). (c) Experimental spin-wave transmission characteristics with no current (dotted, light blue) and with a current of 1 A (solid curve, dark blue) applied to the meander structure. Application of the current leads to the formation of a bandgap of width approximately Δfa=30 MHz, centred on fa=6,500 MHz.
