In-plane and perpendicular magnetic fields dependence of cyclotron resonance in two-dimensional electron systems

The cyclotron resonance of two-dimensional electron systems (2DES) of GaAs/AlGaAs heterostructures is investigated in a tilted magnetic field. In this study, the perpendicular (B⊥) and in-plane (B||) magnetic fields are changed systematically. More than two cyclotron resonances caused by B|| are observed. Further, the enhancement of cyclotron mass by B|| and its dependence on B⊥ and electron concentration of 2DES are also investigated in detail. These phenomena are well explained by the resonant subband Landau level coupling model.