Thrust 1 : Pure Spin and Magnonic Current Control

Dr. Alexander Khitun - University of California Riverside

Magnonic Holography is a novel technique allowing us to take magnonic images of magnetic structures. The principle of this approach is similar to optical holography while exploiting spin waves instead of optical beams. In our experiments, we use several spin wave generators to excite several coherent spin waves propagating in magnetic waveguides with an object of interest placed on the top of the waveguides. The interference pattern produced by the interfering spin waves reveals the unique property (e.g. unique magnonic holographic image of the object). It appears possible to recognize different magnetic states inside a magnetic matrix or obtain the correlation between the input phase pattern and the output voltage.  By utilizing magnonic holographic technique, we are studying spin dynamics in magnetic nanostructures and explore magnon-assisted switching for non-volatile logic.

A set of three holograms obtained for the three configurations of the  micro-magnets as illustrated by the schematics: A) two micro-magnets aligned in the same direction perpendicular to the long axis; B) the magnets are directed in the orthogonal directions; and C) both magnets are directed along the long axis. The red markers show the experimentally measured data (inductive voltage in millivolts) obtained at different phases of the four generated spin waves. The cyan surface is a computer reconstructed 3-D plot. The excitation frequency is 5.4GHz, the bias magnetic field is 1000 Oe, All experiments are done at room temperature F. Gertz, A. Kozhevnikov, Y. Filimonov, and A. Khitun,  Magnetics, IEEE Transactions on (99) (2014).