The strong-coupling polaron in static electric and magnetic fields

This paper is concerned with Fröhlich polarons subject to static electric and magnetic fields in the limit of large electron–phonon coupling. To leading order in the coupling constant, √(α), the ground state energy is shown to be correctly given by the minimum of the Pekar functional including the electromagnetic fields, provided these fields in the Fröhlich model are scaled properly with α. As a corollary, the binding of two polarons in strong magnetic fields is obtained. (paper)