Prof. Jiang Xiao’s group their paper on spin wave diode published on Physical Review X [link]. This paper proposed a novel design of rewritable magnonics hardware architecture and demonstrated of a spin wave diode upon this design.
Magnonics is promising for the next generation energy-saving information technology and hence attracted increasing attention of broad researchers in recent years. The aim of magnonics is to achieve unified information storage and processing using magnons, or spin waves, which are collective quasi-particle excitations of the magnetic moments and can propagate without much energy dissipation. Quite many magnonic structures have been proposed and studied in all sorts of designs, however, a unified and scalable magnonic platform is still lacking.
Using domain walls and surface anisotropy stripes as two different spin wave waveguides [see figure below], we propose a design of magnonic integrated circuits that can in principle perform large number of magnonic operations in a single magnetic wafer, analogy to a silicon wafer for large number of electronic transistors. Since the magnetic texture can be easily modified, this magnonic hardware architecture is reprogrammable, in contrast to most present-day information processing architectures.
Upon this new architecture, we design the simplest magnonic component, a spin wave diode. Making use of the Dzyaloshiskii-Moriya interaction existing in magnetic materials with broken inversion symmetry, we found that the bound spin wave states in a domain wall become chiral and are spatially separated depending on its propagation direction, which enables us to realize the diode effect for spin wave transport [see figure below for the forward on and reverse off]. Furthermore, we demonstrate that the function of the spin wave diode is easily altered from forward-transmitting to reverse-transmitting, etc, by simply moving domain walls via current-induced spin-transfer torque. To our knowledge, this is the first viable design of spin wave diode.