Topological stability versus thermal agitation in a metastable magnetic skyrmion lattice

TL;DR

This study demonstrates that a metastable magnetic skyrmion lattice can be created and maintained at low temperatures by controlling thermal agitation, revealing the interplay between topological stability and thermal effects.

Contribution

It introduces a method to create and control metastable skyrmion lattices through thermal quenching, extending their stability beyond thermodynamic limits.

Findings

Metastable SkL has a lifetime exceeding one week at low temperatures.

Thermal agitation influences the stability and lifetime of the SkL.

Electric heating and rapid cooling enable deterministic SkL creation and annihilation.

Abstract

Topologically stable matters can have a long lifetime, even if thermodynamically costly, when the thermal agitation is sufficiently low. A magnetic skyrmion lattice (SkL) represents a unique form of long-range magnetic order that is topologically stable, and therefore, a long-lived, metastable SkL can form. Experimental observations of the SkL in bulk crystals, however, have mostly been limited to a finite and narrow temperature region in which the SkL is thermodynamically stable; thus, the benefits of the topological stability remain unclear. Here, we report a metastable SkL created by quenching a thermodynamically stable SkL. Hall-resistivity measurements of MnSi reveal that, although the metastable SkL is short-lived at high temperatures, the lifetime becomes prolonged (>> 1 week) at low temperatures. The manipulation of a delicate balance between thermal agitation and the topological stability enables a deterministic creation/annihilation of the metastable SkL by exploiting electric heating and subsequent rapid cooling, thus establishing a facile method to control the formation of a SkL.