Spin-triplet pairing instability in a two-dimensional repulsive Hubbard model

Fuente: arXiv
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Main Authors: Liu, Xing-Can, Song, Yu-Feng, He, Yuan-Yao, Ying, Tao, Zhang, Xueru
Format: Preprint
Published: 2025
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_version_ 1866911284184743936
author Liu, Xing-Can
Song, Yu-Feng
He, Yuan-Yao
Ying, Tao
Zhang, Xueru
author_facet Liu, Xing-Can
Song, Yu-Feng
He, Yuan-Yao
Ying, Tao
Zhang, Xueru
contents The search for superconductivity with unconventional pairing symmetry has been a central focus in the study of strongly correlated electron systems. In this work, we report a numerically exact study of the spin-triplet pairing in a two-dimensional Hubbard model with repulsive interactions, employing Determinant Quantum Monte Carlo method. The model includes next-nearest-neighbor and third-nearest-neighbor hopping terms, and maintains spin balance. By tuning the fermion filling close to a type-II van Hove singularity (vHs) in the model, we numerically investigate the ordering tendencies of several possible pairing channels with different symmetries. Our numerical results provide clear evidence for the spin-triplet $p$-wave pairing instability approaching low temperatures, as revealed by the vertex contribution to the pairing susceptibility. This signature becomes increasingly pronounced as the interaction strength increases in the weak to intermediate regime. We further find that, near the type-II vHs, the dominant spin-spin correlations in the system are ferromagnetic, suggesting its close relation to the spin-triplet pairing instability. Our findings offer a reliable approach to realize the spin-triplet $p$-wave superfluidity in the repulsive Hubbard model, from an unbiased numerical perspective.
format Preprint
id arxiv_https___arxiv_org_abs_2507_09295
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Spin-triplet pairing instability in a two-dimensional repulsive Hubbard model
Liu, Xing-Can
Song, Yu-Feng
He, Yuan-Yao
Ying, Tao
Zhang, Xueru
Quantum Gases
The search for superconductivity with unconventional pairing symmetry has been a central focus in the study of strongly correlated electron systems. In this work, we report a numerically exact study of the spin-triplet pairing in a two-dimensional Hubbard model with repulsive interactions, employing Determinant Quantum Monte Carlo method. The model includes next-nearest-neighbor and third-nearest-neighbor hopping terms, and maintains spin balance. By tuning the fermion filling close to a type-II van Hove singularity (vHs) in the model, we numerically investigate the ordering tendencies of several possible pairing channels with different symmetries. Our numerical results provide clear evidence for the spin-triplet $p$-wave pairing instability approaching low temperatures, as revealed by the vertex contribution to the pairing susceptibility. This signature becomes increasingly pronounced as the interaction strength increases in the weak to intermediate regime. We further find that, near the type-II vHs, the dominant spin-spin correlations in the system are ferromagnetic, suggesting its close relation to the spin-triplet pairing instability. Our findings offer a reliable approach to realize the spin-triplet $p$-wave superfluidity in the repulsive Hubbard model, from an unbiased numerical perspective.
title Spin-triplet pairing instability in a two-dimensional repulsive Hubbard model
topic Quantum Gases
url https://arxiv.org/abs/2507.09295