Ellis, Matthew O A, Fullerton, Eric E. and Chantrell, Roy W. orcid.org/0000-0001-5410-5615 (2016) All-optical switching in granular ferromagnets caused by magnetic circular dichroism. Scientific Reports. 30522. pp. 1-9. ISSN 2045-2322
Abstract
Magnetic recording using circularly polarised femto-second laser pulses is an emerging technology that would allow write speeds much faster than existing field driven methods. However, the mechanism that drives the magnetisation switching in ferromagnets is unclear. Recent theories suggest that the interaction of the light with the magnetised media induces an opto-magnetic field within the media, known as the inverse Faraday effect. Here we show that an alternative mechanism, driven by thermal excitation over the anisotropy energy barrier and a difference in the energy absorption depending on polarisation, can create a net magnetisation over a series of laser pulses in an ensemble of single domain grains. Only a small difference in the absorption is required to reach magnetisation levels observed experimentally and the model does not preclude the role of the inverse Faraday effect but removes the necessity that the opto-magnetic field is 10 s of Tesla in strength.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016, The Author(s). |
Dates: |
|
Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) |
Depositing User: | Pure (York) |
Date Deposited: | 15 Sep 2016 09:00 |
Last Modified: | 16 Oct 2024 13:16 |
Published Version: | https://doi.org/10.1038/srep30522 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1038/srep30522 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104718 |