Artículos de revistas
Optical second harmonic generation in the centrosymmetric magnetic semiconductors EuTe and EuSe
Fecha
2010Registro en:
PHYSICAL REVIEW B, v.81, n.15, 2010
1098-0121
10.1103/PhysRevB.81.155201
Autor
KAMINSKI, B.
LAFRENTZ, M.
PISAREV, R. V.
YAKOVLEV, D. R.
PAVLOV, V. V.
LUKOSHKIN, V. A.
Henriques, Andre Bohomoletz
SPRINGHOLZ, G.
BAUER, G.
ABRAMOF, E.
RAPPL, P. H. O.
BAYER, M.
Institución
Resumen
The magnetic europium chalcogenide semiconductors EuTe and EuSe are investigated by the spectroscopy of second harmonic generation (SHG) in the vicinity of the optical band gap formed by transitions involving the 4f and 5d electronic orbitals of the magnetic Eu(2+) ions. In these materials with centrosymmetric crystal lattice the electric-dipole SHG process is symmetry forbidden so that no signal is observed in zero magnetic field. Signal appears, however, in applied magnetic field with the SHG intensity being proportional to the square of magnetization. The magnetic field and temperature dependencies of the induced SHG allow us to introduce a type of nonlinear optical susceptibility determined by the magnetic-dipole contribution in combination with a spontaneous or induced magnetization. The experimental results can be described qualitatively by a phenomenological model based on a symmetry analysis and are in good quantitative agreement with microscopic model calculations accounting for details of the electronic energy and spin structure.