Heisenberg Ising-Kondo necklace model with transverse field for the heavy fermion compound URuSi.

In this work, we introduce the Heisenberg Ising-Kondo necklace with transverse field as a possible model to describe the heavy-fermion compound URuSi. The physics of this compound presents many open questions, like the transition to the hidden order (HO) phase at T   =  17.5 K. Our Hamiltonian includes elements that come from crystal field processes and Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. The main idea is to allow the transverse field, that a priori acts only in the localized moments, to influence the conduction-electrons via the RKKY interaction. Our results, obtained using a spin-wave approach for a one-dimensional lattice system, reveal a re-entrance behavior on the zero temperature phase diagram. This is an interesting result since combined with the magnetization values of the canted AF phase allow to link this phase with the mixed hidden order/large moment antiferromagnetic (HO/LMAF) phase observed in URuSi.