Optical signatures from magnetic two-dimensional electron gases in magnetic fields to 60 T

We present experiments in the 60 T long-pulse magnet at the Los Alamos National High Magnetic Field Lab focusing on the high-field, low temperature photoluminescence (PL) from modulation-doped ZnSe/Zn(Cd,Mn)Se single quantum wells. High-speed charge-coupled array detectors and the long (2 s) duration of the magnet pulse permit continuous acquisition of optical spectra throughout a single magnet shot. High-field PL studies of the magnetic two-dimensional electron gases at temperatures down to 350 mK reveal clear intensity oscillations corresponding to integer quantum Hall filling factors, from which we determine the density of the electron gas. At very high magnetic fields, steps in the PL energy are observed which correspond to the partial unlocking of antiferromagnetically bound pairs of Mn²⁺ spins.