Finite-temperature dynamics of the Mott insulating Hubbard chain

Journal article

We study the dynamical response of the half-filled one-dimensional Hubbard model for a range of interaction strengths U and temperatures T by a combination of numerical and analytical techniques. Using time-dependent density matrix renormalization group computations we find that the single-particle spectral function undergoes a crossover to a spin-incoherent Luttinger liquid regime at temperatures T∼J=4t2/U for sufficiently large U > 4t. At smaller values of U and elevated temperatures the spectral function is found to exhibit two thermally broadened bands of excitations, reminiscent of what is found in the Hubbard-I approximation. The dynamical density-density response function is shown to exhibit a finite-temperature resonance at low frequencies inside the Mott gap, with a physical origin similar to the Villain mode in gapped quantum spin chains. We complement our numerical computations by developing an analytic strong-coupling approach to the low-temperature dynamics in the spin-incoherent regime.

Authors: Nocera, A; Essler, F; Feiguin, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B
• Volume: 97
• Issue: 4
• Pages: 045146
• Publication date: 2018-01-29
• Acceptance date: 2018-01-12
• DOI: 10.1103/PhysRevB.97.045146
• EISSN: 2469-9969
• ISSN: 2469-9950
• Keywords: Journal Article