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arXiv · 2105.03639

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

Weilun Jiang·Yuzhi Liu·Avraham Klein·Yuxuan Wang·Kai Sun·Andrey V. Chubukov·Zi Yang Meng
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Abstract

The origin of the pseudogap behavior, found in many high-$T_c$ 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, consistent with experimental observations. Our results provide the first unambiguous lattice model realization of a pseudogap state in a strongly correlated system, driven by superconducting fluctuations.

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Weilun Jiang, Yuzhi Liu, Avraham Klein, Yuxuan Wang, Kai Sun, Andrey V. Chubukov, Zi Yang Meng. 2021-05-08. Monte Carlo study of the pseudogap and superconductivity emerging from quantum magnetic fluctuations. https://doi.org/10.1038/s41467-022-30302-x

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