Competition among Superconducting, Antiferromagnetic, and Charge Orders with Intervention by Phase Separation in the 2D Holstein-Hubbard Model

2017/03/31 by Takahiro Ohgoe, Masatoshi Imada · 1 citation
Physics and Astronomy · #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevlett.119.197001

published as Phys. Rev. Lett. 119, 197001 (2017)

arxiv created 2017/11/09 · arxiv updated 2017/11/10

Abstract

Using a variational Monte Carlo method, we study competitions of strong electron-electron and electron-phonon interactions in the ground state of Holstein-Hubbard model on a square lattice. At half filling, an extended intermediate metallic or weakly superconducting (SC) phase emerges, sandwiched by antiferromagnetic and charge order (CO) insulating phases. By the carrier doping into the CO insulator, the SC order dramatically increases for strong electron-phonon couplings, but largely hampered by wide phase separation (PS) regions. Superconductivity is optimized at the border to the PS.

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