Acoustoconductivity of quantum wires

The change in conductivity of quantum wires under the influence of nonequilibrium phonons is considered theoretically. The particular mechanism of this acoustoconductivity (AC) depends on the wire length L. For long wires with L exceeding the localization length, the main effect involves the phonon-induced partial delocalization of carriers. In this case AC will be positive. The electron-phonon scattering rate and, hence, the amplitude of AC, oscillates with the electron density in a wire, having maxima when the Fermi level coincides with the edge of some one-dimensional subband. All these regularities are in agreement with the recent experimental data. In the case of short, ballistic wires, nonequilibrium phonons cause additional backscattering of carriers and AC must be negative. {} 1996 The American Physical Society.