Confinement-deconfinement interplay in quantum phases of doped Mott insulators

It is generally accepted that doped Mott insulators can be well described by the t-J model. In the latter, the electron fractionalization is dictated by the phase string effect. We found that in underdoped regime, the antiferromagnetic and superconducting phases are dual: in the former, holons are confined while spinons are deconfined, and vice versa in the latter. These two phases are separated by a novel phase, the so- called Bose-insulating phase, where both holons and spinons are deconfined. A pair of Wilson loops was found to constitute a complete set of order parameters determining this zero- temperature phase diagram. The quantum transitions between these phases are suggested to be of non-Landau-Ginzburg-Wilson type.