Magnetic susceptibility of the two-dimensional Hubbard model using a power series for the hopping constant

Abstract

The magnetic susceptibility of the two-dimensional repulsive Hubbard model with nearest-neighbor hopping is investigated using the diagram technique developed for the case of strong correlations. In this technique a power series in the hopping constant is used. At half-filling the calculated zero-frequency susceptibility and the square of the site spin reproduce adequately results of Monte Carlo simulations. Also in agreement with numerical simulations no evidence of ferromagnetic correlations was found in the considered range of electron concentrations $0.8\alt\bar{n}\alt 1.2$ for the repulsion parameters $8|t|\le U\le 16|t|$. However, for larger $U/|t|$ and $|1-\bar{n}|\approx 0.2$ the nearest neighbor correlations become ferromagnetic. For $\bar{n}\alt 0.94$ and $\bar{n}\agt 1.06$ the imaginary part of the real-frequency susceptibility becomes incommensurate for small frequencies. The incommensurability parameter grows with departure from half-filling and decreases with increasing the frequency. This behavior of the susceptibility can explain the observed low-frequency incommensurate response observed in normal-state lanthanum cuprates.

12 pages, 11 figures

References in corpus (3)

• The Hubbard model within the equations of motion approach
• A generating functional approach to the Hubbard model
• Quasiparticle states of the Hubbard model near the Fermi level

Cited by in corpus (2)

• Fluctuating charge density waves in the Hubbard model
• Magnetic incommensurability and fluctuating charge density waves in the repulsive Hubbard model