Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys
Journal article, 2019

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 10 7 A cm −2 . Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.

Author

Ezio Iacocca

National Institute of Standards and Technology (NIST)

Chalmers, Physics, Theoretical Physics

University of Colorado at Boulder

T. M. Liu

Stanford University

A. H. Reid

Stanford University

Z. Fu

Tongji University

S. Ruta

University of York

P. W. Granitzka

Stanford University

E. Jal

Stanford University

Stefano Bonetti

Stanford University

Stockholm University

Universita Ca' Foscari Venezia

A. X. Gray

Temple University

Stanford University

C. E. Graves

Stanford University

R. Kukreja

Stanford University

Z. Chen

Stanford University

D. J. Higley

Stanford University

T. Chase

Stanford University

L. Le Guyader

Stanford University

European XFEL

K. Hirsch

Stanford University

H. Ohldag

Stanford University

W. F. Schlotter

Stanford University

G. L. Dakovski

Stanford University

G. Coslovich

Stanford University

M. C. Hoffmann

Stanford University

Sebastian Carron

Stanford University

A. Tsukamoto

Nihon University

A. Kirilyuk

Radboud University

A. V. Kimel

Radboud University

Th Rasing

Radboud University

J. Stöhr

Stanford University

R. F.L. Evans

University of York

T. Ostler

Sheffield Hallam University

University of Liège

R. W. Chantrell

Radboud University

University of York

M. A. Hoefer

University of Colorado at Boulder

T. J. Silva

National Institute of Standards and Technology (NIST)

H. A. Dürr

Stanford University

Uppsala University

Nature Communications

2041-1723 (ISSN) 20411723 (eISSN)

Vol. 10 1 1756

Subject Categories

Other Physics Topics

Condensed Matter Physics

DOI

10.1038/s41467-019-09577-0

More information

Latest update

12/3/2020