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arXiv · 1011.4850

Effects of s,p - d and s - p exchange interactions probed by exciton magnetospectroscopy in (Ga,Mn)N

J. Suffczynski·A. Grois·W. Pacuski·A. Golnik·J. A. Gaj·A. Navarro-Quezada·B. Faina·T. Devillers·A. Bonanni
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Abstract

Near band-gap photoluminescence and reflectivity in magnetic field are employed to determine the exchange-induced splitting of free exciton states in paramagnetic wurtzite Ga1-xMnxN, x < 1%, grown on sapphire substrates by metal-organic vapor phase epitaxy. The band gap is found to increase with x. The giant Zeeman splitting of all three excitons A, B and C is resolved, enabling the determination of the apparent exchange integrals N0alpha(app) = 0.0 +/- 0.1 eV and N0beta(app) = +0.8 +/- 0.2 eV. These non-standard values and signs of the s - d and p - d exchange energies are explained in terms of recent theories that suggest a contribution of the electron-hole exchange to the spin splitting of the conduction band and a renormalization of the free hole spin-splitting by a large p - d hybridization. According to these models, in the limit of a strong p - d coupling, the band gap of (Ga,Mn)N increases with x and the order of hole spin subbands is reversed, as observed.

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J. Suffczynski, A. Grois, W. Pacuski, A. Golnik, J. A. Gaj, A. Navarro-Quezada, B. Faina, T. Devillers, A. Bonanni. 2010-11-22. Effects of s,p - d and s - p exchange interactions probed by exciton magnetospectroscopy in (Ga,Mn)N. https://doi.org/10.1103/physrevb.83.094421

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