Nature of the effective interaction in electron-doped cuprate superconductors: A sign-problem-free quantum Monte Carlo study

Abstract

Understanding the mechanism of Cooper pairing amounts to determining the effective interaction that operates at low energies. Efforts to achieve such a goal for superconducting materials, especially strongly correlated ones, from both bottom-up and top-down approaches, have been plagued by having to use uncontrolled approximations. Here, we perform large-scale, numerically exact, sign-problem-free zero-temperature quantum Monte Carlo simulations on an effective theory based on “hot spots” plus fluctuating collective modes. Because hot spots are clearly identified by angle-resolved photoemission spectroscopy for electron-doped cuprates, we focus our attention on such materials. Our goal is to determine the minimum effective action that can describe the observed superconductivity and charge-density wave. The results suggest that antiferromagnetic fluctuation alone is not sufficient—the effective action needs to be amended with nematic fluctuations. We believe that our results address the pairing mechanism of high-Tc superconductivity in electron-doped cuprates, and they shed light on the pairing mechanism of hole-doped cuprates.

Source-reported materials — not catalogue approval

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