Spectroscopic determination of hole density in the ferromagnetic semiconductor Ga1-xMnxAs

M. J. Seong, S. H. Chun, H. M. Cheong, H. M. Cheong, N. Samarth, A. Mascarenhas

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Abstract

A measurement of the hole density in the ferromagnetic semiconductor Ga1-xMnxAs is notoriously difficult using standard transport techniques due to the dominance of the anomalous Hall effect. Here we report a spectroscopic measurement of the hole density in four Ga1-xMnxAs samples (x = 0, 0.038, 0.061, and 0.083) at room temperature using a Raman-scattering intensity analysis of the coupled plasmon-LO-phonon mode and the unscreened LO phonon. The unscreened LO-phonon frequency linearly decreases as the Mn concentration increases up to 8.3%. The hole density determined from the Raman scattering shows a monotonic increase with increasing x for x≤0.083, exhibiting a direct correlation to the observed Tc. The optical technique reported here provides an unambiguous means of determining the hole density in this important class of "spintronic" semiconductor materials.

Original languageEnglish (US)
Article number033202
Pages (from-to)332021-332024
Number of pages4
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume66
Issue number3
DOIs
StatePublished - Jul 15 2002

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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