We use a recent implementation of the large D expansion in order to
construct the higher-dimensional Kerr-Newman black hole and also new charged
rotating black bar solutions of the Einstein-Maxwell theory, all with rotation
along a single plane. We describe the space of solutions, obtain their
quasinormal modes, and study the appearance of instabilities as the horizons
spread along the plane of rotation. Generically, the presence of charge makes
the solutions less stable. Instabilities can appear even when the angular
momentum of the black hole is small, as long as the charge is sufficiently
large. We expect that, although our study is performed in the limit
D→∞, the results provide a good approximation for charged rotating
black holes at finite D≥6.Comment: 21 pages, 1 figur