Ultrafast transport of laser-excited spin-polarized carriers in Au/Fe/MgO(001).

نویسندگان

  • Alexey Melnikov
  • Ilya Razdolski
  • Tim O Wehling
  • Evangelos Th Papaioannou
  • Vladimir Roddatis
  • Paul Fumagalli
  • Oleg Aktsipetrov
  • Alexander I Lichtenstein
  • Uwe Bovensiepen
چکیده

Hot carrier-induced spin dynamics is analyzed in epitaxial Au/Fe/MgO(001) by a time domain approach. We excite a spin current pulse in Fe by 35 fs laser pulses. The transient spin polarization, which is probed at the Au surface by optical second harmonic generation, changes its sign after a few hundred femtoseconds. This is explained by a competition of ballistic and diffusive propagation considering energy-dependent hot carrier relaxation rates. In addition, we observe the decay of the spin polarization within 1 ps, which is associated with the hot carrier spin relaxation time in Au.

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عنوان ژورنال:
  • Physical review letters

دوره 107 7  شماره 

صفحات  -

تاریخ انتشار 2011