Fundamental energy limits in the physics of nanomagnetic binary switches

Authors: M. Madami, D. Chiucchiù, G. Carlotti, L. Gammaitoni


Bistable nanomagnetic switches can be used to store bits of information, associating each logic state to a different equilibrium orientation of the magnetization. The fundamental limits in minimum energy dissipation are discussed analysing both the reset to 1 operation (0,1 to 1), and two different switching (0 to 1) protocols. Micromagnetic simulations on the switching (0 to 1) operation show that the zero-dissipation limit is attainable but only with one of the two protocols, which does not involve any irreversible entropy increase. Micromagnetic simulations on the reset to 1 operation show that for realistic, elliptical dots with sub-100 nm lateral dimension, the minimum energy dissipation is consistent with the value expected for an ideal bistable switch, E = kBT × ln(2), known as the Landauer limit. The experimental results show a nearly linear decrease of the dissipated energy with the dot volume, ranging from three to one orders of magnitude above the theoretical Landauer limit.