Large splitting of the cyclotron-resonance line in AlxGa1-xN/GaN heterostructures
27 June 2003
Cyclotron-resonance (CR) measurements on two-dimensional (2D) electrons in AlxGa1-xN/GaN heterojunctions reveal large splittings (up to 2 meV) of the CR line for all investigated densities, n(2D), from 1 to 4x10(12) cm(-2) over wide ranges of magnetic field. The features resemble a level anticrossing and imply a strong interaction with an unknown excitation of the solid. The critical energy of the splitting varies from 5 to 12 meV and as rootn(2D). The phenomenon resembles data from AlGaAs/GaAs whose origin remains unresolved. It highlights a lack of basic understanding of a very elementary resonance in solids.