1. Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA, 143 avenue de Rangueil, 31400 Toulouse, France
2. Laboratory of Semiconductor Material, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
3. Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland