Coupling of Bernstein modes in two- and three-dimensional plasmas and effect on their lifetimes

We obtain the dispersion relation and lifetime in the low-wavenumber regime for Bernstein modes in a 2D electron gas when they are coupled electrostatically to the Bernstein modes and magnetoplasmons in the bulk 3D gas. It is shown that the group velocity of the coupled 2D–3D Bernstein modes is affected by the non-local coupling between the Bernstein mode in the 2D system and the bulk modes in the adjoining layers. We also calculate the lifetimes of these coupled modes as a function of magnetic field, which is applied perpendicular to the plane of the 2D electron gas.