Thermal Stability of Metastable Magnetic Skyrmions

Magnetic skyrmions are solitonic nanometer-scale quasiparticles with unique topological properties that could be used in novel information processing and storage devices with low power consumption and high information density. This work studies their stability through two main approaches, finding that small skyrmions possess low internal energy barriers but are stabilized by a large activation entropy. Frustrated exchange at some transition metal interfaces leads to new collapse paths in the form of the partial nucleation of the corresponding antiparticle.

Format: Paperback / softback
Length: 152 pages
Publication date: 05 February 2022
Publisher: Springer Nature Switzerland AG

The energy consumption associated with modern information technologies has been on a rapid rise, fueling the quest for alternative devices for information storage and processing. Magnetic skyrmions, solitonic nanometer-scale quasiparticles, possess unique topological properties akin to a Mobius strip, making them promising candidates for such applications. Skyrmions are envisioned as carriers of information in low-power, high-density devices, offering a solution to the energy challenge. However, for practical use, isolated skyrmions must exhibit long-term stability, which is investigated in this work through two main approaches: the Kramers method in the form of Langer's theory and the forward flux sampling method. Excellent agreement is observed between these methods. It is found that small skyrmions possess low internal energy barriers, but are stabilized by a significant activation entropy. This arises from the existence of stable deformation modes of the skyrmion. Furthermore, frustrated exchange at certain transition metal interfaces leads to the formation of new collapse paths, such as the partial nucleation of corresponding antiparticles like merons and antimerons.

Magnetic skyrmions, as solitonic nanometer-scale quasiparticles, possess unique topological properties, reminiscent of a Mobius strip. Their potential as carriers of information in low-power, high-density devices has sparked significant interest in their application. Skyrmions are envisioned as a solution to the energy challenge, as they offer the potential for efficient information processing and storage with low power consumption.

In this work, the stability of isolated skyrmions is investigated through two main approaches: the Kramers method in the form of Langer's theory and the forward flux sampling method. Excellent agreement is observed between these methods, validating the reliability of the findings. Small skyrmions are found to possess low internal energy barriers, but are stabilized by a large activation entropy. This stabilization is attributed to the existence of stable deformation modes of the skyrmion.

Furthermore, frustrated exchange at certain transition metal interfaces leads to the formation of new collapse paths, such as the partial nucleation of corresponding antiparticles like merons and antimerons. These findings shed light on the behavior and stability of skyrmions, paving the way for their potential use in novel information processing and storage devices.

Weight: 273g
Dimension: 235 x 155 (mm)
ISBN-13: 9783030660284
Edition number: 1st ed. 2021