Magnetic-field-induced singularities in spin dependent tunneling through   InAs quantum dots
  Current steps attributed to resonant tunneling through individual InAs quantum dots embedded in a GaAs-AlAs-GaAs tunneling device are investigated experimentally in magnetic fields up to 28 T. The steps evolve into strongly enhanced current peaks in high fields. This can be understood as a field-induced Fermi-edge singularity due to the Coulomb interaction between the tunneling electron on the quantum dot and the partly spin polarized Fermi sea in the Landau quantized three-dimensional emitter. 
I. Hapke-Wurst, U. Zeitler, H. Frahm, A.G.M. Jansen, R.J. Haug, K.   Pierz