Magnetotunneling spectroscopy of resonant anticrossing in terahertz intersubband emitters

Abstract

Intersubband transport and electroluminescence has been investigated in a double-quantum-well structure based on an intrawell (vertical) THz radiative transition. Magnetotunneling spectroscopy was used to determine subband energies, including the minimum energy separation (∼1.7 meV) between two anticrossed levels. The presence of this anticrossing indicates that in this structure, electron removal from the lower radiative state should be modeled by coherent resonant tunneling rather than incoherent sequential tunneling.