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arXiv · 1703.04146

Pairing instability near a lattice-influenced nematic quantum critical point

D. Labat·I. Paul
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Abstract

We study how superconducting Tc is affected as an electronic system in a tetragonal environment is tuned to a nematic quantum critical point (QCP). Including coupling of the electronic nematic variable to the relevant lattice strain restricts criticality only to certain high symmetry directions. This allows a weak-coupling treatment, even at the QCP. We develop a criterion distinguishing weak and strong Tc enhancements upon approaching the QCP. We show that negligible Tc enhancement occurs only if pairing is dominated by a non-nematic interaction away from the QCP, and simultaneously if the electron-strain coupling is sufficiently strong. We argue this is the case of the iron superconductors.

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D. Labat, I. Paul. 2017-03-12. Pairing instability near a lattice-influenced nematic quantum critical point. https://doi.org/10.1103/physrevb.96.195146

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