Coherent magnetization precession in GaMnAs induced by ultrafast optical excitation

Academic Article


  • The authors use femtosecond optical pulses to induce, control, and monitor magnetization precession in ferromagnetic Ga0.965 Mn0.035 As. At temperatures below ∼40 K, they observe coherent oscillations of the local Mn spins, triggered by an ultrafast photoinduced reorientation of the in-plane easy axis. The amplitude saturation of the oscillations above a certain pump intensity indicates that the easy axis remains unchanged above ∼ TC 2. The authors find that the observed magnetization precession damping (Gilbert damping) is strongly dependent on pump laser intensity, but independent of ambient temperature. They provide a physical interpretation of the observed light-induced collective Mn-spin precession and relaxation. © 2007 American Institute of Physics.
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    Author List

  • Qi J; Xu Y; Tolk NH; Liu X; Furdyna JK; Perakis IE
  • Volume

  • 91
  • Issue

  • 11