Performance of Magnetic Quantum Cellular Automata and Limitations due to Thermal Noise

TL;DR

This paper evaluates the operational limits of magnetic quantum cellular automata, highlighting how thermal noise constrains nanomagnet size and affects reliable logic operation.

Contribution

It provides a simulation-based analysis of nanomagnet dynamics under thermal fluctuations, revealing size limitations for practical quantum cellular automata.

Findings

Switching speed remains unaffected by scaling in the macrospin approximation.

Thermal noise limits nanomagnet size to above 200nm at room temperature.

Thermal fluctuations cause excessive gate errors for smaller nanomagnets.

Abstract

Operation parameters of magnetic quantum cellular automata are evaluated for the purposes of reliable logic operation. The dynamics of the nanomagnets is simulated via the Landau-Lifshitz-Gilbert equations with a stochastic magnetic field corresponding to thermal fluctuations. It is found that in the macrospin approximation the switching speed does not change under scaling of both size and distances between nanomagnets. Thermal fluctuations put a limitation on the size of nanomagnets, since the gate error rate becomes excessive for nanomagnets smaller than 200nm at room temperature.