← Back to search

Phase fluctuations in two-dimensional superconductors and pseudogap phenomenon

Xu-Cheng Wang, Yang Qi

DOI 10.1103/PhysRevB.107.224502 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We study the phase fluctuations in the normal state of generic two-dimensional superconducting systems with s-wave pairing. The effect of phase fluctuations of the pairing fields can be dealt with perturbatively using disorder averaging, after we treat the local superconducting order parameter as a static disordered background. It is then confirmed that the phase fluctuations above the two-dimensional Berezinskii-Kosterlitz-Thouless transition lead to a significant broadening of the single-particle spectrum, giving birth to the pseudogap phenomenon. Quantitatively, the broadening of spectral weights near the BCS gap is characterized by the ratio of the superconducting coherence length and the spatial correlation length of the superconducting pairing order parameter. Our results are tested on the fermionic attractive-U Hubbard model on the square lattice, using the unbiased determinant quantum Monte Carlo method and stochastic analytic continuation.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
Bi2Sr2CaCu2O8+δ

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

—Pressure not reportedunknown

Similar papers