Acoustoconductance of quantum contacts

We describe theoretically the acoustoconductance (AC) of quantum contacts. One characteristic of a contact which distinguishes it from a long, uniform wire is a strong, energy-dependent transmission probability. This has several consequences for AC. Electrons which are forward scattered by phonons can contribute to AC and, furthermore, AC can have positive sign (i.e. a conductance-increase under the influence of phonons). By contrast, for uniform wires only backscattered electrons contribute to AC which always has negative sign.