Putting Pressure on Iron-Arsenide Superconductors
Stepping on a sample, particularly in high heels, is not something most researchers would do. However, by applying pressure comparable to that generated under a stiletto heel, researchers discovered that the low temperature properties of an iron-arsenide-based superconductor where cobalt is substituted for some of the iron, Ca(Fe1-xCox)2As2, can be changed from antiferromagnetic, to superconducting to non-magnetic in a highly controllable manner. This remarkable finding is a consequence of the extreme sensitivity of the various types of order to changes in pressure. This is a unique case where the main states associated with iron-based superconductivity can all be accessed in a single sample by applying modest pressure. This discovery allows for the careful study of how these states interact and may shed light on why and how the iron arsenide materials have such remarkable superconducting properties.