NIST logo

Publication Citation: Ultrafast manetization enhancement in metallic multilayers driven by superdiffusive spin current

NIST Authors in Bold

Author(s): Thomas J. Silva; Justin M. Shaw; Hans T. Nembach; Dennis Rudolf; Chan La-O-Vorakiat; Marco Battiato; Roman Adam; Emrah Turgut; Stefan Mathias; Margaret M. Murnane; Henry C. Kapteyn; Claus M. Schneider;
Title: Ultrafast manetization enhancement in metallic multilayers driven by superdiffusive spin current
Published: September 04, 2012
Abstract: Uncovering the physical mechanisms that govern ultrafast charge and spin dynamics is crucial for understanding correlated matter as well as the fundamental limits of ultrafast spin-based electronics. Spin dynamics in magnetic materials can be driven by ultrashort light pulses, resulting in a transient drop in magnetization within a few hundred femtoseconds. However, a full understanding of femtosecond spin dynamics remains elusive. Here, we spatially separate the spin dynamics using Ni/Ru/Fe magnetic trilayers, where the Ni and Fe layers can be ferro- or antiferromagnetically coupled. By exciting the layers with a laser pulse and probing the magnetization response simultaneously but separately in Ni and Fe, we surprisingly find that optically induced demagnetization of the Ni layer transiently enhances the magnetization of the Fe layer when the two layer magnetications are initially aligned parallel. Our observations are explained by a laser-generated superdiffusive spin current between the layers.
Citation: Nature Communications
Volume: 3
Pages: pp. 1 - 6
Keywords: spin current;ultrafast demagnetization;femtosecond laser;high harmonic generation
Research Areas: Magnetic materials, Condensed Matter Physics, Thin-Films, Physics
PDF version: PDF Document Click here to retrieve PDF version of paper (1MB)