Strong ultrafast demagnetization due to the intraband transitions
arXiv:2401.00099 · doi:10.1088/1361-648X/acf6a2
Abstract
Demagnetization in ferromagnetic transition metals driven by a femtosecond laser pulse is a fundamental problem in solid state physics, and its understanding is essential to the development of spintronics devices. Ab initio calculation of time-dependent magnetic moment in the velocity gauge so far has not been successful in reproducing the large amount of demagnetization observed in experiments. In this work, we propose a method to incorporate intraband transitions within the velocity gauge through a convective derivative in the crystal momentum space. Our results for transition-element bulk crystals (bcc Fe, hcp Co and fcc Ni) based on the time-dependent quantum Liouville equation show a dramatic enhancement in the amount of demagnetization after the inclusion of an intraband term, in agreement with experiments. We also find that the effect of intraband transitions to each ferromagnetic material is distinctly different because of their band structure and spin property differences. Our finding has a far-reaching impact on understanding of ultrafast demagnetization.
24 pages and 6 figures. This is a draft and the final version can be found below
References in corpus (9)
- Super-Diffusive Spin-Transport as a Mechanism of Ultrafast Demagnetization
- High harmonic generation from Bloch electrons in solids
- High harmonic generation in undoped graphene: Interplay of inter- and intraband dynamics
- Antiferromagnetic Domain Wall as Spin Wave Polarizer and Retarder
- Quantum beats in the polarization response of a dielectric to intense few-cycle laser pulses
- Optical spin transfer torque driven domain wall motion in ferromagnetic semiconductor
- All-optical spin switching: A new frontier in femtomagnetism -- A short review and a simple theory
- Ultrafast reduction of exchange splitting in ferromagnetic nickel
- Spin-orbit torque-mediated spin-wave excitation as an alternative paradigm for femtomagnetism