Optical spectroscopy of magnetic 2D electron gases at the Los Alamos pulsed magnetic field facility

Abstract

A brief overview of the magnet technologies at the pulsed field facility at Los Alamos is presented, focusing on the experimental capabilities made possible by the unique generator-driven 60T long-pulse magnet. Optical spectroscopy is one such beneficiary, and recent measurements of semiconductor systems are discussed, including studies of magnetic-disorder annealing in diluted magnetic semiconductors, “dark” excitons in CdSe quantum dots, and in particular, studies of negatively-charged exciton states in magnetic 2D electron gases. Here, the huge Zeeman energy inherent in these magnetically-doped II–VI materials results in a completely spin-polarized electron gas (even at low magnetic fields), and drives an apparent instability of the singlet (spin antiparallel) electrons that are bound to the photohole.