Effective action of the weakly doped t-J model and spin-wave excitations in the spin-glass phase of La_{2-x}Sr_xCuO_4

Andreas Luscher, Alexander I. Milstein, Oleg P. Sushkov

We derive the low-energy effective field theory of the extended t-J model in the regime of light doping. The action includes a previously unknown Berry phase term, which is discuss…