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HL: Fachverband Halbleiterphysik
HL 54: Ultra-fast Phenomena II
HL 54.2: Vortrag
Donnerstag, 20. März 2025, 15:15–15:30, H17
Ultrafast decay of spin-polarization of semiconductor holes measured by attosecond transient absorption spectroscopy — •Lauren Drescher1,2, Kylie Gannan1, and Stephen Leone1 — 1Department of Chemistry, University of California, Berkeley, California 94720, USA — 2Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin, Germany
Carrier excitation by light can lead to spin-polarization in semiconductor conduction and valence bands. While the dynamics of the spin-polarization of conduction band electrons are often well characterized, comparably little is known about the counterpart polarization of valence band holes, due to its much shorter lifetime.
Here we introduce circular dichroic attosecond transient absorption spectroscopy which allows to follow the spin-polarization of materials on attosecond timescales through coupling to the angular momentum of light. Corroborated by real-time time-dependent density functional theory calculations, our experimental results reveal the few femtosecond decay of semiconductor hole spin-polarization in germanium. Our method opens the door to measure spin dynamics in non-magnetic materials with extreme temporal resolution, high spectral resolution and core-level specificity.
Keywords: attosecond; ultrafast; spin-polarization; spin dyanmics; core-level spectroscopy