Divergent nematic susceptibility in an iron arsenide superconductor

ORAL

Abstract

Within the Landau paradigm of continuous phase transitions, ordered states of matter are characterized by a broken symmetry. Although the broken symmetry is usually evident, determining the driving force behind the phase transition can be complicated by coupling between distinct order parameters. We show how measurement of the divergent nematic susceptibility of the iron pnictide superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ distinguishes an electronic nematic phase transition from a simple ferroelastic distortion. These measurements also indicate an electronic nematic quantum phase transition near the composition with optimal superconducting transition temperature.

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Authors

  • Hsueh-Hui Kuo

    Stanford University

  • Jiun-Haw Chu

    University of California, Berkeley

  • James Analytis

    University of California, Berkeley, University of California Berkeley

  • Ian Fisher

    Stanford University, Stanford CA 94305, USA, Stanford University, Stanford Univeristy