Hot electrons in metals for ultrafast magneto-photonics

Seminarium wydziałowe (online)

Dnia 2021-01-26 o godzinie 13:15 odbędzie się seminarium “on-line" (seminarium online odbędzie się z wykorzystaniem platformy ZOOM):

“Hot electrons in metals for ultrafast magneto-photonics"

Serdecznie zapraszamy

Andrzej Maziewski

Jerzy Przeszowski

Hot electrons in metals for ultrafast magneto-photonics

In this talk I will discuss local and non-local dynamics of the laser-excited electron population in metals on a sub-picosecond timescale. There, “hot" non-thermal electrons (those not obeying the Fermi-Dirac distribution) play a crucial role in a plethora of effects including laser-induced demagnetization and long-distance spin transport. Recent experimental results [1,2] indicate the possibility of ballistic spin transfer over 100 nm in Au detected by all-optical time-resolved methods. I will discuss a few main misconceptions about the non-thermal electron population and ultrafast magnetism and highlight the applications of this laser-induced spin transfer for ultrafast magnetism and magneto-photonics. One particularly prominent example of the spin-polarized hot electron transport is the spin-transfer torque (STT)-mediated excitation of high-k (up to 1 nm^{^-1}) spin waves in a orthogonally magnetized ferromagnetic Fe film [3]. The spatial properties of this spin current-driven STT excitation can be inferred from the spectral analysis of these high-frequency spin waves, indicating the STT spatial confinement to less than 2 nm at the Au/Fe interface.

[1] A. Alekhin, I. Razdolski et al., Phys. Rev. Lett. 119, 017202 (2017)
[2] A. Alekhin, I. Razdolski et al. J. Phys.: Condens. Matter 31, 124002 (2019)
[3] I. Razdolski et al., Nat. Comm. 8, 15007 (2017)