Institut Laue-Langevin

Pseudogap temperature as a Widom line in doped Mott insulators

It is a common experience that water is denser than its vapor. However, at sufficiently high pressure, water and vapor cannot be distinguished by their density and there is no boiling point.

Yet, there is a narrow temperature range where viscosity changes rapidly from vapor-like to water- like upon cooling. This paper unveils an unexpected analogy with electrons in materials that become high-temperature superconductors. In these materials, it is known that there is a temperature, the pseudogap temperature, where the electronic properties change rapidly. It is shown here that this signals the existence at lower chemical pressure of two distinct metallic phases with different densities, one of which is the pseudogap phase that has been puzzling physicists for a long time.

Re.: Scientific Reports 2, Article number: 547 doi:10.1038/srep00547