Origin of the pseudogap and its relationship to superconductivity and the Mott state

Determine the origin of the pseudogap in cuprate high-temperature superconductors and rigorously characterize its relationship to superconductivity and to the Mott insulating state, establishing whether and how these phenomena are connected across doping and temperature regimes.

Background

The paper investigates the longstanding mystery of the pseudogap in cuprate superconductors—its origin and connection to superconductivity—using local shot-noise spectroscopy in Bi2Sr2CaCu2O8+δ (Bi-2212). The authors frame this issue as one of the central unresolved topics in quantum materials, contrasting two main hypotheses: local order (e.g., charge density waves) versus preformed Cooper pairs.

Their experiments argue in favor of the pairing scenario by showing that the pseudogap energy coincides with the onset of electron pairing. Although they present evidence addressing the question, they explicitly acknowledge the broader context that the origin and relationships have been widely regarded as open questions in the field.