- Accepted Paper
Transport and Temperature: Exact spectrum and Drude weight for the one-dimensional infinite- Hubbard model
Phys. Rev. Lett. - Accepted 9 September, 2026
DOI: https://doi.org/10.1103/2fwz-cw5h
Phys. Rev. Lett. - Accepted 9 September, 2026
DOI: https://doi.org/10.1103/2fwz-cw5h
Understanding charge transport in strongly correlated systems remains a central challenge in condensed matter physics, while exact analytical results for finite-temperature transport remain rare. Here, we investigate charge transport in the one-dimensional Hubbard model in the infinite-interaction limit. We first construct the exact energy spectrum and eigenstates. Building on these explicit eigenstates, we derive a closed-form analytical expression for the charge Drude weight at arbitrary temperatures in the hole-dilute limit with a fixed number of doped holes, as well as analytical expressions in the low- and high-temperature limits at fixed hole density. We further show that, at low temperatures, the leading correction to the charge Drude weight is linear in when the number of holes is fixed, whereas it is quadratic in when the hole density is fixed. This analytically controlled example highlights the importance of identifying the underlying thermodynamic trajectory when interpreting finite-size numerical studies of charge transport in more general models.
If the author has provided any supplemental materials with this article they will be available upon publication of the version of record.