We show that in a very strong magnetic field B electron-phonon interaction
gives rise to a splitting of Landau levels of a 2D electron into a series of
infinitely degenerate sublevels. We provide both qualitative and quantitative
description of this phenomenon. The cases of interaction with acoustic and
polar optical phonons are considered. The energy distance between nearest
sublevels in both cases tends to zero as B−1/2 at large B.Comment: 4 pages, LaTe