Spectroscopic fingerprints of the frustrated magnetic order in Li2VOSiO4: a t-J model study

We have analyzed theoretically the photoemission spectra of the insulating compound Li2VOSiO4.Recently, this compound has been proposed as the first experimental realization of the frustrated J1-J2 Heisenberg model. Although it is well known that Li2VOSiO4 is magnetically ordered in a collinear arrangement below TN=2.8 K, there is some controversy about the coexistence of two collinear phases above TN. Using a generalized t-J model we have obtained a complex spectral structure that can be traced back to the underlying collinear magnetic structures. We discuss the possibility to use ARPES experiments as a way to discern among the different scenarios proposed in the literature.