Temperature of quasi‐two‐dimensional electron gases under steady‐state terahertz drive

We use photoluminescence to study the time‐average energy distribution of electrons in the presence of strong steady‐state drive at terahertz (THz) frequencies, in a modulation‐doped 125 A AlGaAs/GaAs square well that is held at low lattice temperature TL. We find that the energy distribution can be characterized by an effective electron temperature, Te(≳TL), that agrees well with values estimated from the THz‐illuminated, dc conductivity. This agreement indicates that under strong THz drive, LO phonon scattering dominates both energy and momentum relaxation; that the carrier distribution maintains a heated, thermal form; and that phonon drift effects are negligible.