Mott Transition in the Triangular Lattice Hubbard Model

Although the pseudogap in the weak interaction regime is mostly understood, in the strong interaction regime it still poses an important challenge for the understanding of hole-doped cuprates. It has been proposed that short-range antiferromagnetic (AFM) correlations and Mott physics are part of the mechanism involved in its formation [1]. Critics of this work have argued that the use of small clusters could artificially induce the first order transition [2], or that the apparent Mott transition is just a magnetic transition. To resolve this issue, we solve the Hubbard model using the dynamical cluster approximation on larger triangular clusters, where long-range AFM fluctuations are prohibited by geometrical frustration. Using the Widom line, we show that the Mott transition might exist in such systems and that a pseudogap appears at half filling [3].



References

[1]. G. Sordi et al. Phys. Rev. B, 84, 075161, 2011 .

[2]. A. Wietek et al. Phys. Rev. X 11 , 041013, 2021.

[3]. P.-O. Downey et al. arXiv.2207.08008, 2022.