Optic-phonon-limited transport and anomalous carrier cooling in quantum-wire structures

We present an analytical derivation of the distribution function of a one-dimensional electron gas at high temperature. The quenching of carrier-carrier scattering and the predominance of polar-optic-phonon scattering make the system nonergodic and provide a ‘‘jagged’’ profile to the distribution which results in carrier cooling below the thermal energy. In GaAs quantum wires, this anomalous effect, which is characterized by extremely high carrier mobility, is predicted to occur above ${\mathit{T}}_{\mathit{L}}$=150 K. These conclusions are in excellent agreement with results of Monte Carlo simulations.