Marek Bartkowiak

Abstract The observation of superconductivity in La3Ni2O7–δ under pressure, following the suppression of a high-temperature density wave state, has attracted considerable attention. The nature of this density wave order was not clearly identified. Here we probe the magnetic response of the zero-pressure phase of La3Ni2O7–δ as hydrostatic pressure is applied, and find that the apparent single density wave transition at zero applied pressure splits into two.

Abstract Strongly correlated electron materials are often characterized by competition and interplay of multiple quantum states. For example, in high-temperature cuprate superconductors unconventional superconductivity, spin- and charge-density wave orders coexist. A key question is whether competing states coexist on the atomic scale or if they segregate into distinct regions.