Phenomenological three-orbital spin-fermion model for cuprates

Condensation energy in the spin-fermion model for cuprates

We compute the condensation energy in the spin-fermion model using Scalapino-White relation between the condensation energy and the change in the dynamical structure factor in the normal and the superconducting states. We show that for parameters relevant to cuprates, the extra low-frequency spectral weight associated with the resonance peak in the dynamical structure factor in a superconductor...

Phenomenological lattice model for dynamic spin and charge fluctuations in the cuprates

Motivated by recent neutron scattering experiments on the cuprate superconductors, we present a phenomenological framework describing the dynamics of collective spin excitations coupled to charge/bond order fluctuations. Our quantum lattice model contains two order parameter fields, and can capture spin excitations both in broken-symmetry states with static lattice modulations, as well as in ho...

Quantum-critical theory of the spin- fermion model and its application to cuprates: Normal state analysis

We present the full analysis of the normal state properties of the spin–fermion model near the antiferromagnetic instability in two dimensions. The model describes low-energy fermions interacting with their own collective spin fluctuations, which soften at the antiferromagnetic transition. We argue that in 2D, the system has two typical energies—an effective spin–fermion interaction g and an en...

Scattering Theory for the Spin Fermion Model.

A phenomenological spin–orbit three-body force

In order to improve the description of the N-d vector analyzing powers Ay and iT11 (the so-called Ay puzzle) a spin–orbit three-body force has been introduced. The L · S term in the NN potential has been modified including a two-parameter three-body function depending on the hyperradius ρ. The modification has been performed in channels where the pair of nucleons (i, j) are coupled to spin Sij ...