Hot but Coherent: Doublons at Infinite Temperature in the Hubbard chain
Abstract
We investigate the spectral properties and the dynamics of doublons in the one-dimensional Hubbard model at infinite temperature. Using a Chebyshev expansion approach formulated in the superfermionic representation, we compute the momentum- and frequency-resolved doublon spectral function across a wide range of interaction strengths and in the presence of an external electric field. Increasing the interaction, the spectrum gradually splits into separate bands associated with two-hole and two-particle excitations. Despite the presence of strong correlations, we find that doublons retain their coherence and undergo long-lived Bloch oscillations, as well as rich quantum walk dynamics characterized by light-cone spreadings at strong coupling, which we analyze through the time-and space-resolved Green's function.
Keywords
Cite
@article{arxiv.2509.20504,
title = {Hot but Coherent: Doublons at Infinite Temperature in the Hubbard chain},
author = {Cătălin Paşcu Moca and Balázs Dóra and Gergely Zaránd},
journal= {arXiv preprint arXiv:2509.20504},
year = {2025}
}