Room temperature terahertz intersubband polariton electroluminescence

Strong light-matter coupling in intersubband systems has received increased attention recently, as new effects including the parametric generation of non-classical light and the dynamical Casimir-effect are predicted in systems where the coupling energy is a significant fraction of the excitation energy. This can be achieved with parabolic quantum wells, allowing for high electron densities and temperature independence due to equidistant energy states. We employ this in combination with the high radiative efficiency predicted with high Rabi frequencies a key advantage of strong coupling in the terahertz regime to demonstrate for the first time terahertz intersubband electroluminescence at room temperature.