TY  - JOUR
A1  - Deb, Marwan
A1  - Popova, Elena
A1  - Jaffrès, Henri-Yves
A1  - Keller, Niels
A1  - Bargheer, Matias
T1  - Polarization-dependent subpicosecond demagnetization in iron garnets
T2  - Physical review : B, covering condensed matter and materials physics
N2  - Controlling the magnetization dynamics at the fastest speed is a major issue of fundamental condensed matter physics and its applications for data storage and processing technologies. It requires a deep understanding of the interactions between the degrees of freedom in solids, such as spin, electron, and lattice as well as their responses to external stimuli. In this paper, we systematically investigate the fluence dependence of ultrafast magnetization dynamics induced by below-bandgap ultrashort laser pulses in the ferrimagnetic insulators BixY3-xFe5O12 with 1 xBi 3. We demonstrate subpicosecond demagnetization dynamics in this material followed by a very slow remagnetization process. We prove that this demagnetization results from an ultrafast heating of iron garnets by two-photon absorption (TPA), suggesting a phonon-magnon thermalization time of 0.6 ps. We explain the slow remagnetization timescale by the low phonon heat conductivity in garnets. Additionally, we show that the amplitudes of the demagnetization, optical change, and lattice strain can be manipulated by changing the ellipticity of the pump pulses. We explain this phenomenon considering the TPA circular dichroism. These findings open exciting prospects for ultrafast manipulation of spin, charge, and lattice dynamics in magnetic insulators by ultrafast nonlinear optics.
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/61296
SN  - 2469-9950
SN  - 2469-9969
VL  - 106
IS  - 18
PB  - American Institute of Physics, American Physical Society
CY  - Woodbury, NY
ER  -