Magnonic Holographic Memory

Collective oscillation of spins in magnetic lattice known as spin waves (magnons) possess relatively long coherence length at room temperature, which makes it possible to build submicrometer scale holographic devices similar to the devices developed in optics. In this paper, we present a prototype 2-bit magnonic holographic memory. The memory consists of the double-cross waveguide structure made of Y₃Fe₂(FeO₄)₃ with magnets placed on the top of waveguide junctions. Information is encoded in the orientation of the magnets, while the read-out is accomplished by the spin waves generated by the microantennas placed on the edges of the waveguides. The interference pattern produced by multiple spin waves makes it possible to build a unique holographic image of the magnetic structure and recognize the state of each magnet. The development of magnonic holographic devices opens a new horizon for building scalable holographic devices compatible with conventional electronic devices.