Spectroscopic fingerprints of the frustrated magnetic order in Li2VOSiO4

I. JAVIER HAMAD; L. O. MANUEL; A. E. TRUMPER

Buenos Aires. Argentina

Workshop; At the frontier of the condensed matter III; 2006

Centro Atomico Constituyentes

We have analyzed theoretically the photoemission spectra ofthe insulating compound Li2VOSiO4. Recently, this compoundhas been proposed as the first experimental realization of the frustratedJ1 −J2 Heisenberg model. Although it is well known thatLi2VOSiO4 is magnetically ordered in a collinear arrangementbelow Tc =2.8K, there is some controversy about the values of itsexchange interactions J1 and J2. Using a generalized t −J modelto compute the spectral functions, we have obtained a complexspectral structure that can be traced back to the presence of ferromagneticand antiferromagnetic chains in the collinear magneticstructure. We also discuss the possibility to use ARPES experimentsas a way to discern among the different exchange interactionparameters reported in the literature.