S duality and dyonic p-brane solutions in type II string theory

We show how a solitonic ''magnetically'' charged p-brane solution of a given supergravity theory, with the magnetic charge carried by an antisymmetric tensor gauge field, can be generalized to a dyonic solution. We discuss the cases of ten-dimensional and eleven-dimensional supergravity in more detail and a new dyonic five-brane solution in ten dimensions is given. Unlike the purely electrically or magnetically charged five-brane solution the dyonic five-brane contains nonzero Ramond-Ramond fields and is, therefore, an intrinsically type II solution. The solution preserves half of the type II spacetime supersymmetries. It is obtained by applying a solution-generating SL(2,R) X SL(2,R) S duality transformation to the purely magnetically charged five-brane solution. One of the SL(2,R) duality transformations is basically an extension to the type II case of the six-dimensional Z(2) string-string duality. We also present an action underlying the type IIB supergravity theory.