2008/04/02 by J. Wang, Łukasz Cywiński, L. Cywinski +6 · 2 citations
Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #Semiconductor Quantum Structures and Devices #ZnO doping and properties #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.77.235308
published as Phys. Rev. B 77, 235308 (2008) · 7 pages, 6 figures
arxiv created 2008/04/02 · openalex publication_date 2008/06/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have studied ultrafast photoinduced demagnetization in GaMnAs via two-color time-resolved magneto-optical Kerr spectroscopy. Below band gap midinfrared pump pulses strongly excite the valence band, while near-infrared probe pulses reveal subpicosecond demagnetization that is followed by an ultrafast (\ensuremath∼1 ps) partial recovery of the Kerr signal. Through comparison with InMnAs, we attribute the signal recovery to an ultrafast energy relaxation of holes. We propose that the dynamical polarization of holes through p\text\ensuremath-d scattering is the source of the observed probe signal. These results support the physical picture of femtosecond demagnetization proposed earlier for InMnAs, identifying the critical roles of both energy and spin relaxation of hot holes.