Anisotropic interaction between electrons and piezoelectric phonons in semiconductor heterojunctions in magnetic field

In any 2D electron system with asymmetric quantizing potential in the presence of a magnetic field parallel to the 2D plane, different interactions between the electron system and any phonons having mutually opposite directions of wave vectors (anisotropic interaction) appear, which leads to the emergence of a new unusual thermomagnetic effect: the electromotive force for homogeneous heating of the electron system appears. This universal phenomenon is analyzed for the case of anisotropic interaction between electrons and piezoelectric phonons in GaAs-GaAlAs heterojunction. The consequence of this anisotropic interaction is an anomalous temperature dependence of the thermomagnetic effect at low temperature.