Worasaran, ThanapatIkeda, Matthias S.Palmstrom, Johanna C.Straquadine, Joshua A. W.Kivelson, Steven A.Fisher, Ian R.2021-07-172021-07-172021-07-172021-05-2810.1126/science.abb9280https://infoscience.epfl.ch/handle/20.500.14299/180068WOS:000656432400048Quantum criticality may be essential to understanding a wide range of exotic electronic behavior; however, conclusive evidence of quantum critical fluctuations has been elusive in many materials of current interest. An expected characteristic feature of quantum criticality is power-law behavior of thermodynamic quantities as a function of a nonthermal tuning parameter close to the quantum critical point (QCP). Here, we observed power-law behavior of the critical temperature of the coupled nematic/structural phase transition as a function of uniaxial stress in a representative family of iron-based superconductors, providing direct evidence of quantum critical nematic fluctuations in this material. These quantum critical fluctuations are not confined within a narrow regime around the QCP but rather extend over a wide range of temperatures and compositions.Multidisciplinary SciencesScience & Technology - Other Topicscritical-pointsusceptibilitytext::journal::journal article::research article