Magnetic-Field-Induced Delocalized to Localized Transformation in GaAs:N

The use of a high magnetic field (57 T) to study the formation and evolution of nitrogen (N) cluster and supercluster states in GaAs: N is demonstrated. A magnetic field is used to lift the conduction band edge and expose resonant N cluster states so that they can be directly experimentally investigated. The reduction of the exciton Bohr radius also results in the fragmentation of N supercluster states, enabling a magnetic field induced delocalized to localized transition. The application of very high magnetic fields thus presents a powerful way to probe percolation phenomena in semiconductors with bound and resonant isoelectronic cluster states. DOI: 10.1103/PhysRevLett.110.156405