Spin diffusion and spin conductivity in the 2d Hubbard model

Abstract

We study the spin diffusion and spin conductivity in the square lattice Hubbard model by using the finite-temperature Lanczos method. We show that the spin diffusion behaves differently from the charge diffusion and has a nonmonotonic $T$ dependence. This is due to a progressive liberation of charges that contribute to spin transport and enhance it beyond that active at low temperature due to the Heisenberg exchange. We further show that going away from half-filling and zero magnetization increases the spin diffusion, but that the increase is insufficient to reconcile the difference between the model calculations and the recent measurements on cold-atoms.

9 pages, 5+4 figures

References in corpus (5)

• Theory of universal incoherent metallic transport
• Spin transport in Heisenberg antiferromagnets
• Charge transport in the Hubbard model at high temperatures: triangular versus square lattice
• Absence of a quantum limit to charge diffusion in bad metals
• Antiferromagnetic Spin Fluctuations in the Metallic Phase of Quasi-Two-Dimensional Organic Superconductors