Doping and temperature-evolution of Fermi arcs in moderately underdoped cuprate high temperature superconductors (HTSCs)—a joint density of states perspective

Central to the microscopic theory of cuprate HTSCs is unveiling the low-energy electronic excitations in the PG phase, where the electronic density of states in the vicinity of the chemical potential is suppressed even above the superconducting (SC) critical temperature). Employing an autocorrelation analysis of angle resolved photoemission spectroscopy (ARPES) data, we have investigated the evolution of the joint density of states (JDOS) in the pseudogap (PG) phase of slightly underdoped Bi₂Sr₂CaCu₂O_8+δ (Bi2212) cuprate high temperature superconductors (HTSCs) for different temperatures and carrier concentrations.We have observed that the changes in the JDOS patterns with increasing either temperature or carrier concentration can be interpreted in terms of expanding Fermi arc contours. Qualitatively, this is consistent with theoretical scenarios of the pseudogap phase being a phase incoherent d-wave superconductor, in which the Fermi arcs are described in terms of a subtle balance between temperature-dependent lifetime broadening of the single-particle excitations and the magnitude of the pairing gap.