Phase transition arising from the underscreened Anderson lattice model: A candidate concept for explaining hidden order in URu2Si2

Abstract

We analyze a type of phase transition that appears in the spin-rotationally invariant form of the underscreened Anderson lattice model and we obtain, with decreasing temperature, a continuous transition with the opening of a gap. We suggest that this model might describe the ``hidden-order'' transition in URu${}_{2}$Si${}_{2}$. We also examine the gaps that appear in the electronic dispersion relations of the bands of different orbital character and compare our results with those found through photoelectron spectroscopy.