Power dissipation in spintronic devices out of thermodynamic equilibrium

TL;DR

This paper estimates quantum limits of power dissipation in spintronic devices, showing potential for energy efficiency far below thermal limits by controlling spin relaxation rates.

Contribution

It provides a theoretical analysis of power dissipation in spintronic quantum dots, highlighting conditions for minimal energy loss and offering design insights for efficient devices.

Findings

Dissipation can be much less than ~kT per bit with slow spin relaxation.

Spin dynamics modeled via Bloch equations under magnetic noise.

Guidelines for engineering energy-efficient spintronic devices.

Abstract

Quantum limits of power dissipation in spintronic computing are estimated. A computing element composed of a single electron in a quantum dot is considered. Dynamics of its spin due to external magnetic field and interaction with adjacent dots is described via the Bloch equations. Spin relaxation due to magnetic noise from various sources is described as coupling to a reservoir. Resulting dissipation of energy is calculated and is shown to be much less than the thermal limit, ~kT per bit, if the rate of spin relaxation is much slower than the switching rate. Clues on how to engineer an energy efficient spintronic device are provided.