4 Deformed Richardson-Gaudin model
P. Kulish, Alexander Stolin, H. Johannesson
Abstract
The Richardson-Gaudin model describes strong pairing correlations of fermions confined to a\nfinite chain. The integrability of the Hamiltonian allows the algebraic construction of its eigenstates. In this\nwork we show that the quantum group theory provides a possibility to deform the Hamiltonian preserving\nintegrability. More precisely, we use the so-called Jordanian r-matrix to deform the Hamiltonian of the\nRichardson-Gaudin model. In order to preserve its integrability, we need to insert a special nilpotent term\ninto the auxiliary L-operator which generates integrals of motion of the system. Moreover, the quantum\ninverse scattering method enables us to construct the exact eigenstates of the deformed Hamiltonian. These\nstates have a highly complex entanglement structure which require further investigation.