Nano Logic Circuits with Spin Wave Bus

Abstract

We propose and analyze logic circuits utilizing spin waves as a physical mechanism for information transmission and processing. The novelty of this approach is that information transmission is accomplished without charge transfer. A bit of information is encoded into the phase of spin wave propagating in a ferromagnetic film - spin wave bus. The communication between the spin wave bus and outer devices is performed in a wireless manner via a magnetic field. We describe an example of logic device using high frequency transmission lines to excite and detect spin waves. The performance is illustrated by numerical modeling based on the experimental data for spin wave excitation and propagation in NiFe film. We also propose an original scheme for output signal amplification based on the effect of hole-mediated ferromagnetism. Potentially, logic circuits with spin wave bus may be beneficial in terms of power consumption and resolve the interconnect problem. Another expected benefit is in the enhanced logic functionality. It is possible to achieve all advantages of the phase logic using spin waves for information processing. The shortcomings and limitations of circuits with spin wave bus are discussed