Source capture
Authors Yongping Wei, Xun Liu, Fan Yang, Mi Jiang
arXiv / Publisher http://arxiv.org/abs/2604.07185v1
PDF https://arxiv.org/pdf/2604.07185v1
Relevance score 5.413
Primary category Not available in this batch.
Published Not available in this batch.
Research paradigm Theoretical
Sample form Unknown

Summary

Inspired by the vertically electric-field-tunable superconducting properties of Ruddlesden–Popper bilayer nickelate La3Ni2O7, this study employs the dynamic cluster quantum Monte Carlo method to solve the imbalanced two-orbital bilayer Hubbard model. By analyzing the electric-field-induced pairing symmetry and its evolution under undoped, hole-doped, and electron-doped conditions, we find that the s±-wave pairing originating from the dz2 orbital is suppressed, while the interlayer mismatch of the dz2 orbital and the transfer of electrons to the dx2-y2 orbital drive a pairing symmetry transition from s±-wave to d-wave. Interestingly, the d-wave pairing arising from the dx2-y2 orbital exhibits a dome-shaped behavior as a function of electric field strength. The large-scale many-body calculations are consistent with the predictions of weak-coupling methods, providing new insights into the superconducting mechanism of RP nickelates.

Materials

Methods

  • dynamical cluster approximation (DCA)
  • continuous-time auxiliary-field quantum Monte Carlo (CT-AUX QMC)
  • Bethe-Salpeter equation

Keywords

  • pairing symmetry transition
  • dome shaped behavior
  • electric field
  • orbital mismatch

Highlights

  • The d-wave pairing exhibits a dome-shaped behavior as a function of electric field strength.
  • The large-scale many-body calculations are consistent with weak-coupling predictions.

Conclusions

  • The s±-wave pairing from the d_z2 orbital is suppressed by the electric field, while d-wave pairing from the dx2-y2 orbital emerges with a dome-like behavior.
  • The transition from s±-wave to d-wave occurs due to interlayer orbital mismatch and electron transfer to the dx2-y2 orbital.

Main claims

  • Applying a perpendicular electric field to bilayer La3Ni2O7 suppresses s±-wave pairing from dz2 orbital and induces d-wave pairing from dx2-y2 orbital
    • Evidence: DCA calculations show that eigenvalues for s± pairing decrease with increasing V, while d-wave eigenvalues exhibit dome-like behavior, with maximum d-wave Tc exceeding s± Tc at intermediate V

Workflow

  • Model construction — s±-wave pairing suppressed, d-wave pairing emerges with electric field
    • Materials: Two-orbital bilayer Hubbard model
    • Methods: Dynamical cluster approximation (DCA) with CT-AUX solver
    • Observations: BSE eigenvalues for s± and d-wave channels
  • Data analysis — Pairing symmetry transition from s± to d-wave
    • Methods: Extrapolation of Tc from eigenvalues; Orbital-resolved pair-field susceptibility
    • Observations: Dome-like behavior of d-wave Tc with electric field