Direct surface cyclotron resonance terahertz emission from a quantum   cascade structure
  A strong magnetic field applied along the growth direction of a semiconductor quantum well gives rise to a spectrum of discrete energy states, the Landau levels. By combining quantum engineering of a quantum cascade structure with a static magnetic field, we can selectively inject electrons into the excited Landau level of a quantum well and realize a tunable surface emitting device based on cyclotron emission. By applying the appropriate magnetic field between 0 and 12 T, we demonstrate emission from a single device over a wide range of frequencies (1-2 THz and 3-5 THz). 
Fran\c{c}ois-R\'egis Jasnot (LPA), Louis-Anne De Vaulchier (LPA), Yves   Guldner (LPA), G\'erald Bastard (LPA), Angela Vasan...
cond-mat.mes-hall cond-mat.mtrl-sci