Thermoelectric signature of the nematic phase in hole-doped iron-based superconductors

Abstract

Studies of copper-based superconductors demonstrate how their phase diagram becomes more complex as experimental probes improve, able to distinguish among subtly different electronic phases. One of those phases, nematicity, has become a matter of great interest also in iron-based superconductors, where it is detected deep in the tetragonal state. Here, we present the evolution of in-plane Nernst effect anisotropy in strain-detwinned Ca(Fe1−xCox)2As2 single crystals. We interpret the observed behavior using an approach developed to describe the nematic order parameter in liquid crystals. We also apply the same model to data from other superconductors, Ba(Fe1−xCox)2As2 and YBa2Cu3Oy. We conclude the observed broken rotational symmetry of the electronic system is a consequence of the emerging thermodynamic electronic nematic order at a temperature much higher than the onset of the magnetic and structural transitions.

Source-reported materials — not catalogue approval

Similar papers