Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 36: Poster Ib

HL 36.5: Poster

Dienstag, 8. März 2016, 15:00–19:00, Poster A

B-induced inhomogeneous Broadening of the Electronic Spin Flip Resonance in Zn_.94Mn_.06Se near the Metal-Insulator Transition — •Alexander Gerhard Knapp¹, Michael Hetterich², and Jean Geurts¹ — ¹Universität Würzburg, Experimentelle Physik 3, Würzburg, Germany — ²Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

The diluted magnetic wide-gap semiconductor Zn_1−xMn_xSe allows the independent tuning of the magnetic and the electronic properties by variation of either the Mn content or the dopant concentration. The strong s-d exchange coupling between the Mn-iond d-levels and the s-type donor electrons gives rise to a giant Zeeman splitting in an external B-field. This short-range exchange interaction with the spatially randomly distributed Mn should result in a B-induced broadening of the donor energy distribution. We have investigated this effect for Zn_.94Mn_.06Se:Cl with various Cl-concentrations up to 4.5 10¹⁷ cm⁻³ by electron spin flip Raman spectroscopy (ESFRS) at T = 1.6 K. In ESFRS, the spin flip transition of the donor-bound electron is mediated by optically induced donor-bound excitons (D⁰,X), which results in a sharp resonance of the ESFRS efficiency when the exciting laser photon energy matches the (D⁰,X) energy. Therefore, we interpret the spectral dependence of the ESFRS-efficiency (resonance profile) in terms of the energy distribution of the donor states. We actually observe a significant broadening of the ESFRS resonance profiles with increasing B-field, up to 11.5 meV (FWHM) for B = 5 T.