Marco Madami
Dipartimento di Fisica e Geologia, Universita' degli studi di Perugia

Spin-wave logic: a new paradigm for low energy computing

It is widely acknowledged that Moore's law the exponential scaling of semiconductor performance in the past few decades is about to come to an end. The research field for future beyond CMOS computing technology is wide open for complete new ideas and paradigms. A promising direction is based on the idea to use the spin degree of freedom of electrons (instead of their sole electric charge) to encode, process and transmit information. An entire research field spintronics has raised and flourished from this idea. There are different possible approaches to use electron spins for information processing: one straightforward way is to use the magnetic states of interacting magnetic particles to build magnetic bits and magnetic logic gates. A less straightforward way is to use collective excitations of a spin-lattice - spin-waves - for information transport and processing. Both approaches share a clear advantage from the point of view of energy dissipation with respect to the CMOS technology because they are not directly affected by Ohmic losses. The usage of spin-waves [1,2] provides an additional degree of freedom in data processing, it opens the way to non-Boolean computing algorithm, and allows for a further downscale of the computing elements. Wave-based computing provides relatively simple and elegant ways for e.g. doing linear filtering, or calculating Fourier transforms. These are important computing tasks which may be responsible for the bulk of the power consumption especially in specialized tasks like image processing algorithms and in neural networks. This presentation will be focused on giving a wide picture of the state-of-the-art in the research field of spin-wave logic by reviewing recent experimental and simulation results from different research groups working in the field.

[1] G. Csaba, Á. Papp, W. Porod - Physics Letters A, 2017
[2] A. V. Chumak, V. I. Vasyuchka, A. A. Serga and B. Hillebrands - Nature Physics 11, (2015)