Intermediate phase at the metal-insulator boundary in a magnetically doped two-dimensional electron system

A magnetotransport study in magnetically doped (Cd,Mn)Te two-dimensional quantum wells reveals an apparent metal-insulator transition as well as an anomalous intermediate phase just on its metallic side. This phase is characterized by colossal magnetoresistancelike phenomena, which may be due to the phase separation of the electron fluid and the associated emergence of ferromagnetic bubbles.