A fermion dynamical symmetry model of high-temperature. Superconductivity and antiferromagnetic order

Yang Sun

The mechanism that leads to high‐temperature superconductivity in cuprates remains an open question despite intense study for nearly two decades. Here, we introduce an SU(4) model for cuprate systems having many similarities to dynamical symmetries known to play an important role in nuclear structure physics and in elementary particle physics. Analytical solutions in three dynamical symmetry limits of this model are found: an SO(4) limit associated with antiferromagnetic order; an SU(2) limit that may be interpreted as a d‐wave pairing condensate; and an SO(5) limit that may be interpreted as a doorway state between the antiferromagnetic order and the superconducting order. It is demonstrated that with a slightly broken SO(5) but under constraint of the parent SU(4) symmetry, the model is capable of describing the rich physics that is crucial in explaining why cuprate systems that are antiferromagnetic Mott insulators at half filling become superconductors through hole doping.

Mike Guidry

Simon Friederich, H. C. Krahl, CHRISTOF WETTERICH

The phases with spontaneously broken symmetries corresponding to antiferromagnetic and $d$-wave superconducting order in the two-dimensional $t\ensuremath{-}{t}^{'}$-Hubbard model are investigated by means of the functional renormalization group. The introduction of composite boson fields in the magnetic, charge density, and superconducting channels allows an efficient parametrization of the four-fermion vertex and the study of regimes where either the antiferromagnetic or superconducting order parameter, or both, are nonzero. We compute the phase diagram and the temperature dependence of the order parameter below the critical temperature, where antiferromagnetic and superconducting order show a tendency of mutual exclusion.

Richard M. Friedberg, T.D. Lee

Jan Dobeš

The SU(4) algebraic model of high-temperature superconductivity is studied employing the boson mapping techniques. The bosonization of the model enables us to get exact numerical solution of the model. The order parameters are discussed. The situation close to the SO(5) dynamical symmetry limit is interpreted as a modelling case for the behaviour of $D$-wave superconducting and antiferromagnetic phases in cuprates.

V. Cataudella, Giuseppe Iadonisi, D. Ninno +1 more