arXiv:1904.10782 · Physical review. B./Physical review. B
Magnetic susceptibility and simulated neutron signal in the two-dimensional Hubbard model
J. P. F. LeBlanc, Shaozhi Li, Xi Chen, Ryan Levy, Andrey E. Antipov, Andrew J. Millis, Emanuel Gull
Abstract
We compute dynamic spin susceptibilities in the two-dimensional Hubbard model using the method of dual fermions, and we provide a comparison to lattice Monte Carlo and cluster dynamical mean-field theory. We examine the energy dispersion identified by peaks in $\mathrm{Im}\ensuremath{\chi}(\ensuremath{\omega},q)$, which define spin modes, and we compare the exchange scale and magnon dispersion to neutron experiments on the parent ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$ cuprate. We present the evolution of the spin excitations as a function of Hubbard interaction strengths and doping, and we explore the particle-hole asymmetry of the spin excitations. We also study the correlation lengths and the spin excitation dispersion peak structure, and we find a Y-shaped dispersion similar to neutron results on doped ${\mathrm{HgBa}}_{2}{\mathrm{CuO}}_{4+\ensuremath{\delta}}$.