Spin-exchange-induced dimerization of an atomic 1-D system

TL;DR

This study reveals a one-dimensional atomic system exhibiting a charge density wave instability driven by spin exchange, with potential applications in magnetic memory, supported by experimental STM data and theoretical analysis.

Contribution

It demonstrates a novel 1-D CDW instability caused by spin exchange, supported by direct STM measurements and first-principles calculations, highlighting magnetic independence of dimers.

Findings

Observation of CDW instability on a metallic substrate

Identification of ferromagnetic state as the cause of instability

Potential for binary spin-memory applications

Abstract

Using low-temperature scanning tunneling microscopy, we demonstrate an unambiguous 1-D system that surprisingly undergoes a CDW instability on a metallic substrate. Our ability to directly and quantitatively measure the structural distortion of this system provides an accurate reference for comparison with first principles theory. In comparison to previously proposed physical mechanisms, we attribute this particular 1-D CDW instability to a ferromagnetic state. We show that though the linear arrayed dimers are not electronically isolated, they are magnetically independent, and hence can potentially serve as a binary spin-memory system.