2017/07/31 by Pengfei Zhang · 1 citation
Physics and Astronomy · #cond-mat.str-el #hep-th
paper · pdf · doi:10.1103/physrevb.96.205138
published as Phys. Rev. B 96, 205138 (2017) · 9 pages, 9 figures
arxiv created 2017/08/07 · arxiv updated 2017/11/29
The Sachdev-Ye-Kitaev (SYK) model is a concrete model for non-Fermi Liquid with maximally chaotic behavior in 0+1-d. In order to gain some insights into real materials in higher dimensions where fermions could hop between different sites, here we consider coupling a SYK lattice by a constant hopping. We call this dispersive SYK model. Focusing on 1+1-d homogeneous hopping, by either tuning temperature or the relative strength of random interaction (hopping) and constant hopping, we find a crossover between a dispersive metal to an incoherent metal, where dynamic exponent z changes from 1 to ∞. We study the crossover by calculating spectral function, charge density correlator and the Lyapunov exponent. We further find the Lyapunov exponent becomes larger when the chemical potential is tuned to approach a Van Hove singularity because of the large density of states near the Fermi suface. The effect of the topological non-trivial bands is also discussed.