1. Nematic fluctuations mediated superconductivity revealed by anisotropic strain in Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$
- Author
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Philippe, J. -C., Lespinas, A., Faria, J., Forget, A., Colson, D., Houver, S., Cazayous, M., Sacuto, A., Paul, I., and Gallais, Y.
- Subjects
Superconductivity (cond-mat.supr-con) ,Condensed Matter::Soft Condensed Matter ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter::Superconductivity ,Condensed Matter - Superconductivity ,FOS: Physical sciences - Abstract
Anisotropic strain is an external field capable of selectively addressing the role of nematic fluctuations in promoting superconductivity. We demonstrate this using polarization-resolved elasto-Raman scattering to probe the evolution of nematic fluctuations under strain in the normal and superconducting states of the paradigmatic iron-based superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. In the non-superconducting parent compound BaFe$_2$As$_2$ we observe a strain-induced suppression of the nematic susceptibility which follows the expected behavior of an Ising order parameter under a symmetry breaking field. For the superconducting compound, the suppression of the nematic susceptibility correlates with the decrease of the superconducting critical temperature $T_c$. Our results indicate a significant contribution of nematic fluctuations to electron pairing and validate theoretical scenarios of enhanced $T_c$ near a nematic quantum critical point., 5 pages, 3 figures + SM
- Published
- 2022