Theory of giant magnetoresistance at misfit interfaces

TL;DR

This paper presents a theoretical analysis of giant magnetoresistance at misfit interfaces, showing how resistance oscillates with magnetic flux depending on lattice mismatch and is enhanced at incommensurate lattice ratios.

Contribution

It introduces a model linking lattice mismatch ratios to magnetoresistance oscillations and highlights the role of enlarged unit cells in this phenomenon.

Findings

Resistance oscillates with magnetic flux depending on lattice ratio

Magnetoresistance is enhanced at incommensurate lattice relations

The size of the enlarged unit cell is crucial for resistance behavior

Abstract

We study theoretically the resistance at the interface between the two planar systems with different lattice constants a and b. The resistance and the effect of the magnetic field depends sensitively on the ratio a/b. The size of the enlarged unit cell $\lambda = n_Aa = n_Bb$ ($n_A$, $n_B$: integers) is the crucial quantity, and the magnetic flux penetrating this enlarged unit cell determines the oscillation of the resistance. Therefore, the magnetoresistance is very much enhanced at (nearly) incommensurate relation between a and b.