2020/06/30 by Zhaoyu Han, Steven A. Kivelson, Hong Yao · 1 citation
Physics and Astronomy · #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.125.167001
published as Phys. Rev. Lett. 125, 167001 (2020) · 12 pages, 4 figs
arxiv created 2020/10/14 · arxiv updated 2020/10/15
We analyze the quantum phase diagram of the Holstein-Hubbard model using an asymptotically exact strong-coupling expansion. We find all sorts of interesting phases including a pair-density wave (PDW), a charge 4e (and even a charge 6e) superconductor, regimes of phase separation, and a variety of distinct charge-density-wave (CDW), spin-density-wave (SDW) and superconducting regimes. We chart the crossovers that occur as a function of the degree of retardation, i.e. the ratio of characteristic phonon frequency to the strength of interactions.