Time-Dependent Density Functional Theory for Spin Dynamics
- 75 Downloads
With the development of ultrashort sub-picosecond laser pulses, the last two decades have witnessed the emergence of a new field of magnetism, namely, femtomagnetism. This consists of controlling the magnetic interactions by using purely optical stimuli at sub-picosecond timescales, where both the exchange interaction and the magnetic anisotropy cannot be considered constant. The modeling of such phenomena is at present populated by semiempirical theories, which heavily rely on assumptions about the dominant interactions responsible for the dynamics and the system intrinsic properties (e.g., the conductivity). However, in the last few years, there have been a few attempts to look at the problem from a purely ab initio point of view, namely, by using time-dependent density functional theory. Here we will review the progress in this field and show how a theory not biased by assumptions can shed light into the fundamental aspects of the laser-induced magnetization dynamics. In particular we will discuss the ultrafast demagnetization of transition metals both in their cluster and bulk form and the possibility of spin transfer between sublattices in compounds containing magnetic ions. The chapter is also complemented by a short review of time-dependent spin density functional theory in the context of spin dynamics.
This work (MS, JS, and SS) was supported by Science Foundation Ireland (Grants No. 14/IA/2624 and No. 16/US-C2C/3287). We gratefully acknowledge the Irish Centre for High-End Computing (ICHEC) for the provision of computational facilities. We also acknowledge the Trinity Centre for High Performance Computing (TCHPC) for use of computational resources. SS would like to thank DFG for funding through TRR227.
- Cinchetti M, Albaneda MS, Hoffmann D, Roth T, Wuestenberg JP, Krauss M, Andreyev O, Schneider HC, Bauer M, Aeschlimann M (2006) Spin-flip processes and ultrafast magnetization dynamics in co: unifying the microscopic and macroscopic view of femtosecond magnetism. Phys Rev Lett 97(17):177201ADSCrossRefGoogle Scholar
- La-O-Vorakiat C, Siemens M, Murnane MM, Kapteyn HC, Mathias S, Aeschlimann M, Grychtol P, Adam R, Schneider CM, Shaw JM, Nembach H, Silva TJ (2009) Ultrafast demagnetization dynamics at the m edges of magnetic elements observed using a tabletop high-harmonic soft x-ray source. Phys Rev Lett 103:257402ADSCrossRefGoogle Scholar
- Ostler TA, Barker J, Evans RFL, Chantrell RW, Atxitia U, Chubykalo-Fesenko O, El Moussaoui S, Le Guyader L, Mengotti E, Heyderman LJ, Nolting F, Tsukamoto A, Itoh A, Afanasiev D, Ivanov BA, Kalashnikova AM, Vahaplar K, Mentink J, Kirilyuk A, Rasing T, Kimel AV (2012) Ultrafast heating as a sufficient stimulus for magnetization reversal in a ferrimagnet. Nat Commun 3:666ADSCrossRefGoogle Scholar
- Vodungbo B, Gautier J, Lambert G, Sardinha AB, Lozano M, Sebban S, Ducousso M, Boutu W, Li K, Tudu B, Tortarolo M, Hawaldar R, Delaunay R, Lopez-Flores V, Arabski J, Boeglin C, Merdji H, Zeitoun P, Luening J (2012) Laser-induced ultrafast demagnetization in the presence of a nanoscale magnetic domain network. Nat Commun 3:999ADSCrossRefGoogle Scholar