Inverse photoemission in strongly correlated electron systems

Based on exact results for small clusters of t-J models, we point out the existence of several distinct channels in the inverse photoemission (IPSE) spectrum. Holelike quasiparticles can either be annihilated completely or leave behind a variable number of spin excitations, which formed the dressing cloud of the annihilated hole. In the physical parameter regime the latter processes carry the bulk of IPES weight, and, although the Fermi surface takes the form of hole pockets, the spectral function including the spin excitation bands is reminiscent of free electrons.