The low spin moment in LaOFeAs is due to a hidden multipole order caused by spin orbital ordering

Francesco Cricchio, Oscar Granas, Lars Nordstrom

An antiferro-magnetic (AF) low moment solution, 0.4 ${\mu }_{\mathrm{B}}$/Fe, is found in the case of LaOFeAs for an intermediately strong Coulomb interaction $U$ of 2.5--3.0 eV. This sol…