  Using the symmetry of the near-horizon geometry and applying quantum field
theory of a complex scalar field, we study the spontaneous pair production of
charged scalars from near-extremal rotating, electrically and/or magnetically
charged black holes. Analytical expressions for pair production, vacuum
persistence and absorption cross section are found, and the spectral
distribution is given a thermal interpretation. The pair production in
near-extremal black holes has a factorization into the Schwinger effect in AdS
and Schwinger effect in Rindler space, measuring the deviational from
extremality. The associated holographical correspondence is confirmed at the
2-point function level by comparing the absorption cross section ratio as well
as the pair production rate both from the gravity and the conformal field
theories. The production of monopoles is discussed.
