Abstract

We elaborate on the Kotliar-Ruckenstein slave-boson method for two-dimensional Hubbard model in order to study strongly correlated electron systems at arbitrary interaction strength U without finite size effects. Thereby, we introduce auxiliary bosonic fields to transform the quartic interaction term into a quadratic expression of bosons that create doubly occupied lattice sites, and recover the original Hilbert space by means of constraints. We then employ a spiral magnetic mean-field ansatz and evaluate fluctuations around the respective symmetry-broken ground state in order to provide a stability analysis, and investigate dynamic excitation spectra.

Applying the one-band Hubbard model with finite next-to-nearest neighbor hopping as a minimal model for cuprate systems, we recover characteristic features of the cuprate phase diagram for hole- and electron-doping. Thereby, we reproduce the Yamada relation for the spin-incommensurability in La-based cuprates [1] and resolve the intricacy of intertwined spin and charge order in the electron-doped cuprate NCCO in agreement with experimental evidence from resonant x-ray scattering (RXS) [2].
[1] M. Klett, J. Beyer, D. Riegler, J. Seufert, P. Wölfle, S. Rachel and R. Thomale, arXiv:2312.11628 (2023)
[2] D. Riegler, J. Seufert, E. H. da Silva Neto, P. Wölfle, R. Thomale, and M. Klett, Phys. Rev. B 108, 195141 (2023)