Ultrafast reduction of the total magnetization in iron

作者：Fognini A^*; Michlmayr T U; Salvatella G; Wetli C; Ramsperger U; Baehler T; Sorgenfrei F; Beye M; Eschenlohr A; Pontius N; Stamm C; Hieke F; Dell'Angela M; de Jong S; Kukreja R; Gerasimova N; Rybnikov V; Al Shemmary A; Redlin H; Raabe J; Foehlisch A; Duerr H A; Wurth W; Pescia D; Vaterlaus A; Acremann Y

来源：Applied Physics Letters, 2014, 104(3): 032402.

DOI：10.1063/1.4862476

Surprisingly, if a ferromagnet is exposed to an ultrafast laser pulse, its apparent magnetization is reduced within less than a picosecond. Up to now, the total magnetization, i.e., the average spin polarization of the whole valence band, was not detectable on a sub-picosecond time scale. Here, we present experimental data, confirming the ultrafast reduction of the total magnetization. Soft x-ray pulses from the free electron laser in Hamburg (FLASH) extract polarized cascade photoelectrons from an iron layer excited by a femtosecond laser pulse. The spin polarization of the emitted electrons is detected by a Mott spin polarimeter.

• 出版日期2014-1-20