Critical role of next-nearest-neighbor interlayer interaction in magnetic behavior of magnetic/nonmagnetic multilayers

TL;DR

This paper investigates how next-nearest-neighbor interlayer exchange interactions significantly influence the magnetic behavior of magnetic semiconductor multilayers, revealing long-range coupling effects enabled by the system's quasi-one-dimensional structure and long Fermi wavelengths.

Contribution

It demonstrates the importance of next-nearest-neighbor interactions in magnetic multilayers and quantifies their strength relative to nearest-neighbor couplings.

Findings

Step-wise magnetoresistance behavior observed

Next-nearest-neighbor coupling can be up to 24% of nearest-neighbor

Long-range interactions facilitated by system's quasi-one-dimensionality

Abstract

We report magnetoresistance data in magnetic semiconductor multilayers, which exhibit a clear step-wise behavior as a function of external field. We attribute this highly non-trivial step-wise behavior to next-nearest-neighbor interlayer exchange coupling. Our microscopic calculation suggests that this next-nearest-neighbor coupling can be as large as 24% of the nearest-neighbor coupling. It is argued that such unusually long-range interaction is made possible by the quasi-one-dimensional nature of the system and by the long Fermi wavelength characteristic of magnetic semiconductors.