Seminarium Fizyki Materii Skondensowanej

I will present [1] an analytically solvable model for correlated electrons, which is able to capture the major Fermi surface modifications occurring in both hole- and electron-doped cuprates as a function of doping. The proposed Hamiltonian, which represents an extension of the Hatsugai-Kohmoto model [2], qualitatively reproduces the results of numerically demanding many-body calculations, here obtained [1] using the dynamical vertex approximation in its ladder implementation [3]. Our analytical theory provides a transparent description of a precise mechanism, capable of driving the formation of disconnected segments along the Fermi surface (the highly debated “Fermi arcs”), as well as the opening of a pseudogap in hole and electron doping. This occurs through a specific mechanism: The electronic states on the Fermi arcs remain intact, while the Fermi surface part where the gap opens transforms into a Luttinger arc. This finding might support the incorporation of the Hatsugai-Kohmoto physics as a non-trivially correlated starting point for approximating the solution of Hubbard-like Hamiltonians [4].
[1] P. Worm, M. Reitner, K. Held, and A. Toschi, Phys. Rev. Lett. 133,166501 (2024);
[2] Y. Hatsugai and M. Kohmoto, J. Phys. Soc. Jpn. 61, 2056 (1992);
[3] A. Toschi, A.A. Katanin, and K. Held, Phys. Rev. B 75, 045118 (2007); G. Rohringer et al., Rev. Mod. Phys. 90, 025003 (2018).
[4] P. Mai, J. Zhao, G. Tenkila, N. A. Hackner, D. Kush, D. Pan, andP. Phillips, Nat. Phys. (2025).