Journal ArticleEmergence of nodal Bogoliubov quasiparticles across the transition from the pseudogap metal to the d-wave superconductorChristos, Maine; Sachdev, Subir<title>Abstract</title> <p>We model the pseudogap state of the hole- and electron-doped cuprates as a metal with hole and/or electron pocket Fermi surfaces. In the absence of long-range antiferromagnetism, such Fermi surfaces violate the Luttinger requirement of enclosing the same area as free electrons at the same density. Using the Ancilla theory of such a pseudogap state, we describe the onset of conventional<italic>d</italic>-wave superconductivity by the condensation of a charge<italic>e</italic>Higgs boson transforming as a fundamental under the emergent SU(2) gauge symmetry of a background<italic>π</italic>-flux spin liquid. In all cases, we find that the<italic>d</italic>-wave superconductor has gapless Bogoliubov quasiparticles at 4 nodal points on the Brillouin zone diagonals with significant velocity anisotropy, just as in the BCS state. This includes the case of the electron-doped pseudogap metal with only electron pockets centered at wavevectors (<italic>π</italic>, 0), (0, <italic>π</italic>), and an electronic gap along the zone diagonals. Remarkably, in this case, too, gapless nodal Bogoliubov quasiparticles emerge within the gap at 4 points along the zone diagonals upon the onset of superconductivity.</p>Springer Nature2024-12-0110521332npj Quantum Materials912397-4648https://doi.org/10.1038/s41535-023-00608-02245246National Science Foundation