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Monte Carlo study of the pseudogap and superconductivity emerging from quantum magnetic fluctuations

ABSTRACT: The origin of the pseudogap behavior, found in many high-Tc superconductors, remains one of the greatest puzzles in condensed matter physics. One possible mechanism is fermionic incoherence, which near a quantum critical point allows pair formation but suppresses superconductivity. Employing quantum Monte Carlo simulations of a model of itinerant fermions coupled to ferromagnetic spin fluctuations, represented by a quantum rotor, we report numerical evidence of pseudogap behavior, emerging from pairing fluctuations in a quantum-critical non-Fermi liquid. Specifically, we observe enhanced pairing fluctuations and a partial gap opening in the fermionic spectrum. However, the system remains non-superconducting until reaching a much lower temperature. In the pseudogap regime the system displays a “gap-filling" rather than “gap-closing" behavior, similar to the one observed in cuprate superconductors. Our results present direct evidence of the pseudogap state, driven by superconducting fluctuations. The origin of pseudogap in high-Tc superconductors remains a big puzzle. Here, the authors report numerical evidence of pseudogap behavior employing Quantum Monte Carlo algorithm emerging from pairing fluctuations in a quantum-critical non-Fermi liquid, similar to the pseudogap phase observed in cuprate superconductors.

SUBMITTER: Jiang W

PROVIDER: S-EPMC9098861 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

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