Photoluminescence in Pulsed Magnetic Fields*

Magneto-photoluminescence (MPL) spectroscopy has proved to be a powerful technique for investigating optical transitions in quantum well-type semiconductor heterostructures. The spectra are strongly influenced by electron-electron interactions and the method is widely used in the study of two-dimensional electron systems (2DES) to probe the integer and fractional quantum Hall effect and magnetic field induced Wigner crystallization. We have established a magneto-optical facility at NHMFL-LANL and have undertaken a comprehensive investigation of magneto-excitonic and Landau transitions using both steady state (to 18 Tesla) and pulsed (to 50 and 65 Tesla) magnetic fields applied perpendicular (Faraday geometry) and parallel (Voigt geometry) to the growth axis of these 2DES. The experimental techniques, optical layout, and data acquisition will be reviewed in some detail. The pulsed field mode requires that the spectroscopic data acquisition to be obtained in 1-2 msec. in the 'flat-top' region at the peak of the field. We have measured a broad range of such structures in high magnetic fields as a function of temperatures and high pressure. Examples of MPL spectra of GaAs-based coupled double quantum wells, modulation-doped quantum wells, and other related semiconductor heterojunction structures will be given. *The National High Magnetic Field Laboratory (NHMFL) is supported through the NSF Cooperative Agreement # DMR 90-16241, State of Florida, and the US Dept. of Energy. Work at NHMFL was undertaken in collaboration with Y. Kim, Northeastern University and D.G. Rickel, NHMFL, LANL, S. Tozer, NHMFL, FSU, E.D. Jones and J.A. Simmonds, Sandia National Laboratory, and Kyu-Seok Lee, Electronics and Telecommunications Research Institute, Taejon, Korea. (1) D. Heiman: Semiconductors and Semimetals, ed. D.G. Seiler and C.L. Little (Academic press, 1992) Vol. 36, Chap. 1, p. 1 and references therein.