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arXiv · 2509.24415

Strong enhancement of d-wave superconductivity in an extended checkerboard Hubbard ladder

Xichen Huang·Saisai He·Jize Zhao·Zhong-Bing Huang
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Abstract

By employing the density-matrix renormalization group method, we study an extended checkerboard Hubbard model on the two-leg ladder, which includes an intraplaquette nearest-neighbour attraction V. The simulated results show that V plays a significant role in enhancing the d-wave superconductivity when the electron density is close to half-filling. In the homogeneous case t'=t (t and t' are the intraplaquette and interplaquette hopping integrals), large critical |Vc| is required to induce the superconducting ground state. With decreasing t', |Vc| is substantially diminished and the pair state has a nearly C4 symmetry. In the extremely inhomogeneous case t'<0.2t, the system transits to the d-wave superconducting phase at V\sim-0.3t and V\sim-0.4t for U=8t and U=12t, respectively, accompanying with a shift of spin and single-particle excitations from gapless to gapped type.

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Xichen Huang, Saisai He, Jize Zhao, Zhong-Bing Huang. 2025-10-20. Strong enhancement of d-wave superconductivity in an extended checkerboard Hubbard ladder. https://arxiv.org/abs/2509.24415

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