Spin-charge gauge approach to "Pseudogap": theory versus experiments

We propose an explanation of several experimental features related to the ‘‘pseudogap’’ in high Tc cuprates in terms of a spin-charge gauge theory. In this approach, based on a formal spin-charge separation applied to the t–J model, the low energy effective action describes gapful spinons (with a theoretically derived doping dependence of the gap) and holons with ‘‘small’’ Fermi surface interacting via a gauge field. The main effect of gauge fluctuations is to introduce a dissipation. The competition between the two energy scales is the root in our approach of many phenomena peculiar to transport properties of the ‘‘pseudogap phase’’. A good agreement is found between the experimental data and theoretically derived doping and temperature dependence of many physical quantities, such as in-plane and out-of-plane resistivity, in-plane magnetoresistance, far infrared electronic AC conductivity and spin lattice relaxation rate.