See also: D. Schmerek, V.T. Dolgopolov, M. Halland, A.A. Shashkin, C. Steinebach, E.V. Devyatov, A.V. Aristov, J.P. Kotthaus
PACS: 72.20.My, 73.40.Kp, 72.70.+m, 73.40.Hm, 73.50.Td, 05.50.+q, 73.20.Dx