The transport-structural correspondence across the nematic phase transition probed by elasto X-ray diffraction

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Electronic nematicity in iron pnictides couples lattice and electron properties.
• Nematic fluctuations and order parameters can be probed via structural and transport observables.

Purpose of the Study:

• To investigate the nemato-elastic and nemato-transport couplings in iron pnictides.
• To utilize elasto X-ray diffraction for probing nematicity in a single sample.
• To explore the interplay between nematicity and superconductivity.

Main Methods:

• Simultaneous transport and X-ray diffraction measurements.
• In-situ tunable strain application (elasto X-ray diffraction).
• Measurement of shear modulus, elastoresistivity, orthorhombicity, and resistivity anisotropy.

Main Results:

• The ratio of transport to structural quantities remained nearly constant over a 74 K range.
• Agreement was observed between the ordered and disordered phases.
• Elasto X-ray diffraction proved effective in probing nematic couplings.

Conclusions:

• Elasto X-ray diffraction is a powerful technique for studying nematicity and its couplings.
• The findings have implications for understanding nearby superconductivity.
• Measurements in the large strain limit reveal the intertwined nature of nematicity and breakdown of mean-field theory.