Effects of band mixing on hole tunneling times in GaAs/AlAs double‐barrier heterostructures

The tunneling time of holes in GaAs/AlAs double‐barrier heterostructures is calculated within the envelope function approximation, including band‐mixing effects. The phase delay time is obtained from the energy derivative of the total phase shift of the wave function upon tunneling. The results show clearly that mixing plays a very important role in hole tunneling. In particular, our study suggests that the conventional effective mass models (without band mixing) can significantly overestimate the heavy hole tunneling time and thus are not suitable for estimation of the hole tunneling time. It is also demonstrated that the effect of band mixing on hole tunneling times becomes more important for thicker barriers.