Superconductivity enhancement and particle-hole asymmetry: Interplay with electron attraction in doped Hubbard model
Zhi Xu, Hong-Chen Jiang, Yi-Fan Jiang
SciPost Phys. 19, 137 (2025) · published 25 November 2025
- doi: 10.21468/SciPostPhys.19.5.137
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Abstract
The role of near-neighbor electron attraction $V$ in strongly correlated systems has been at the forefront of recent research of unconventional superconductivity. However, its implications in the doped Hubbard model on expansive systems remain predominantly unexplored. In this study, we employ the density-matrix renormalization group to examine its effect in the lightly doped $t$-$t'$-Hubbard model on six-leg square cylinders, where $t$ and $t'$ are the first and second neighbor electron hopping amplitudes. In the electron-doped regime ($t'>0$), we find that attractive $V$ can substantially enhance superconducting correlations, driving the system into a pronounced superconducting phase when the attraction exceeds a modest value $V_c ≈ 0.5t$. In contrast, in the hole-doped regime ($t' <0$), while heightened superconducting correlations have also been observed in the charge stripe phase, the systems remain insulating with pronounced charge density wave order. Our results demonstrate the importance of the electron attraction in boosting superconductivity in broader doped Hubbard systems and highlight the asymmetry between the electron and hole-doped regimes.
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Zhi Xu,
- 2 3 Hong-Chen Jiang,
- 1 Yi-Fan Jiang
- 1 上海科技大学 / ShanghaiTech University
- 2 Stanford University [SU]
- 3 SLAC National Accelerator Laboratory [SLAC]
- National Key Research and Development Program of China (through Organization: Ministry of Science and Technology of the People's Republic of China [MOST])
- National Natural Science Foundation of China [NSFC]
- United States Department of Energy [DOE]
