# An alternative to the spin-coupled interface resistance for describing heat generation

## TL;DR

This paper proposes an alternative approach to describe heat generation in spin valves, challenging the traditional spin-coupled interface resistance model and introducing effective resistances for better interpretation.

## Contribution

It introduces effective resistances as a new way to accurately describe spin-dependent heat generation, replacing the problematic spin-coupled interface resistance model.

## Key findings

- Spin-dependent heat generation cannot generally be interpreted as Joule heating.
- The spin-coupled interface resistance can be negative in some cases.
- Effective resistances provide a more consistent description of heat generation.

## Abstract

Using a macroscopic approach, we studied theoretically the heat generation in a typical spin valve with nonmagnetic spacer layer of finite thickness. Our analysis shows that the spin-dependent heat generation cannot be interpreted as the Joule heating of the spin-coupled interface resistance except for some special segments. Moreover, the spin-coupled interface resistance can be negative in certain situation, and thus its "Joule heating" should be understood instead as the work done by the extra field in the ferromagnetic layers and at the spin-selective interfaces. Effective resistances are proposed as alternatives so that the spin-dependent heat generation can still be expressed in a form resembling Joule's law.