Response time of the double-barrier heterostructures with resonant tunneling

We have shown that, first, the response time (tau (resp)) of the double-barrier heterostructures (DBHS) can be much smaller as well as much larger than the quasibound-state lifetime in the quantum well (tau (dwell)). Second, the real part of the DBHS conductance can be negative and large at frequencies higher than the reciprocal tau (dwell) in the DBHSs with heavily doped collector. The displacement current and Coulomb interaction of the electrons in the quantum well with emitter and collector are responsible for the effects. A simple analytical expression for the impedance of DBHS has been derived, it is in fairly good agreement with experimental data. An equivalent circuit is proposed.