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arXiv · 2404.11950

Pair-density-wave phase of strongly interacting electrons on the triangular lattice: A variational Monte Carlo study

Jiucai Wang·Wen Sun·Hao-Xin Wang·Zhaoyu Han·Steven A. Kivelson·Hong Yao
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Abstract

A robust theory of the mechanism of pair density wave (PDW) superconductivity (i.e. where Cooper pairs have nonzero center of mass momentum) remains elusive. Here we explore the triangular lattice $t$-$J$-$V$ model, a low-energy effective theory derived from the strong-coupling limit of the Holstein-Hubbard model, by large-scale variational Monte Carlo simulations. When the electron density is sufficiently low, the favored ground state is an s-wave PDW, consistent with results obtained from previous studies in this limit. Additionally, a PDW ground state with nematic d-wave pairing emerges in the intermediate range of electron densities and phonon frequencies. For these s-wave and d-wave PDWs arising in states with spontaneous breaking of time-reversal and inversion symmetries, PDW formation derives from valley-polarization and intra-pocket pairing.

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Jiucai Wang, Wen Sun, Hao-Xin Wang, Zhaoyu Han, Steven A. Kivelson, Hong Yao. 2024-04-18. Pair-density-wave phase of strongly interacting electrons on the triangular lattice: A variational Monte Carlo study. https://doi.org/10.1103/gvw1-xk98

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