Spin-charge separation in the single-hole-doped Mott antiferromagnet - art. no. 075102

The motion of a single hole in a Mott antiferromagnet is investigated based on the t-J model. An exact expression of the energy spectrum is obtained, in which the irreparable phase string effect [Phys. Rev. Lett. 77, 5102 (19 96)] is explicitly present. By identifying the phase string effect with spi n backflow, we point out that spin-charge separation must exist in such a s ystem: the doped hole has to decay into a neutral spinon and a spinless hol on, together with the phase string. We show that while the spinon remains c oherent, the holon motion is deterred by the phase string, resulting in its localization in space. We calculate the electron spectral function which e xplains the line shape of the spectral function as well as the "quasipartic le" spectrum observed in angle-resolved photoemission experiments. Other an alytic and numerical approaches are discussed based on the present framewor k.