Magnetotransport in Zener tunneling regime in a high-mobility two-dimensional hole gas

In a high-mobility two-dimensional hole gas (2DHG) in C-doped (001) GaAs/Al(0.4)Ga(0.6)As quantum wells, we observe sharp features in the differential magnetoresistance, which we interpret as the Zener-tunneling peak and valley associated with the commensuration transition of Landau orbits. Comparison of data with that in GaAs/Al(0.3)Ga(0.7)As 2D electron gas suggests that the amplitude of Zener oscillations in a 2DHG is strongly damped. The data indicate the significant role of band structures in nonlinear transport in 2D electronic systems.