Fractionalized Fermi liquids and the pseudogap

Ya-Hui Zhang, Subir Sachdev A

This paper paper proposes a theoretical framework to study the pseudogap metal phases in hole doped cuprates. The authors use an ancilla qubit parton theory that give rise to a fractional Fermi liquid phase with Fermi arcs .The theory also predicts a ghost Fermi surface in the critical region between the pseudogap metal and the overdoped Fermi liquid, which can be tested in future experiments at optimal doping.

Subir Sachdev A

Junhyun Lee, Steven White, Subir Sachdev A

Alexander Nikolaenko, Jonas von Milczewski, Darshan G. Joshi +1 more

The pseudogap metal phase of hole-doped cuprates can be described by small Fermi surfaces of electronlike quasiparticles, which enclose a volume violating the Luttinger relation. This violation requires the existence of additional fractionalized excitations which can be viewed as fractionalized remnants of the paramagnon. We fractionalize the paramagnon into the bosonic spinons of the spin liquid described by the ${\mathbb{CP}}^{1}$ U(1) gauge theory, and we present a gauge theory of the bosonic spinons, a Higgs field, and an ancilla layer of fermions coupled to the original electrons. Along with the small Fermi surface pseudogap metal, this theory displays conventional phases: the large Fermi surface Fermi liquid with a low-energy paramagnon mode, and phases with spin density wave order. We describe the evolution of the electronic photoemission spectrum across these quantum phase transitions. We consider both the two-sublattice N\'eel and incommensurate spin density wave phases, and we find that the latter has spiral spin correlations.

N. S. Vidhyadhiraja, Alexandru Macridin, Cengiz Şen +2 more

We explore the Matsubara quasiparticle fraction and the pseudogap of the two-dimensional Hubbard model with the dynamical cluster quantum Monte Carlo method. The character of the quasiparticle fraction changes from non-Fermi-liquid, to marginal Fermi liquid, to Fermi liquid as a function of doping, indicating the presence of a quantum critical point separating non-Fermi-liquid from Fermi-liquid character. Marginal Fermi-liquid character is found at low temperatures at a very narrow range of doping where the single-particle density of states is also symmetric. At higher doping the character of the quasiparticle fraction is seen to cross over from Fermi liquid to marginal Fermi liquid as the temperature increases.