Non-collinear spin states in bottom-up fabricated atomic chains

TL;DR

This paper demonstrates the bottom-up assembly of chiral spin-spirals in atomic chains, showing how interatomic distance tuning can control their rotational properties, advancing potential spintronics applications.

Contribution

It introduces a method to engineer and control non-collinear spin states in atomic chains via atomic spacing adjustments.

Findings

Spin-spirals are induced by Heisenberg and Dzyaloshinskii-Moriya interactions.

Interatomic Fe distance controls the spin-spiral's period and sense.

Experimental assembly using a scanning tunneling microscope tip.

Abstract

Non-collinear spin states with unique rotational sense, such as chiral spin-spirals, are recently heavily investigated because of advantages for future applications in spintronics and information technology and as potential hosts for Majorana Fermions when coupled to a superconductor. Tuning the properties of such spin states, e.g., the rotational period and sense, is a highly desirable yet difficult task. Here, we experimentally demonstrate the bottom-up assembly of a spin-spiral derived from a chain of Fe atoms on a Pt substrate using the magnetic tip of a scanning tunneling microscope as a tool. We show that the spin-spiral is induced by the interplay of the Heisenberg and Dzyaloshinskii-Moriya components of the Ruderman-Kittel-Kasuya-Yosida interaction between the Fe atoms. The relative strengths and signs of these two components can be adjusted by the interatomic Fe distance, which enables tailoring of the rotational period and sense of the spin-spiral.