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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
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Abstract

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 discussed in detail. We use this effective field theory to calculate spin-wave excitations in the disordered spin spiral state of La_{2-x}Sr_xCuO_4 (the spin-glass phase). We predict an excitation spectrum with two distinct branches: The in-plane mode has the usual linear spin-wave dispersion and the out-of-plane mode shows non-trivial doping dependent features. We also calculate the intensities for inelastic neutron scattering in these modes.

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Andreas Luscher, Alexander I. Milstein, Oleg P. Sushkov. 2007-03-07. 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. https://doi.org/10.1103/physrevb.75.235120

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