Electronic nematicity in correlated metals often occurs alongside another instability such as magnetism. The question thus remains whether nematicity alone can drive unconventional superconductivity or anomalous (quantum critical) transport in such systems. In FeSe, nematicity emerges in isolation, providing a unique opportunity to address this question. Studies to date, however, have proved inconclusive; while signatures of nematic criticality are observed upon sulfur substitution, they appear to be quenched by the emergent magnetism under the application of pressure. Here, we study the temperature and pressure dependence of the low-temperature resistivity of FeSe1-xSx crystals at x values beyond the nematic quantum critical point. Two distinct components to the resistivity are revealed; one that is suppressed with increasing pressure and one that grows upon approaching the magnetic state at higher pressures. These findings hint that nematic and magnetic critical fluctuations in FeSe1-xSx are completely decoupled, in marked contrast to other Fe-based superconductors.
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The authors acknowledge enlightening discussions with M. Berben, C. Duffy, B. Goutéreaux, R. Hinlopen, Y.-T. Hsu, and C. Pépin. J.A. acknowledges the support of the EPSRC-funded CMP-CDT (Ref. EP/L015544/1) and an EPSRC Doctoral Prize Fellowship (Ref. EP/T517872/1). A.C. and S.F. acknowledge the support of the EPSRC (Ref. EP/R011141/1). We also acknowledge the support of the High Field Magnet Laboratory (HFML) at Radboud University (RU), member of the European Magnetic Field Laboratory (EMFL), and the former Foundation for Fundamental Research on Matter (FOM), which is financially supported by the Netherlands Organization for Scientific Research (NWO) (Grant No. 16METL01), “Strange Metals.” Part of this work was also supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreements no. 835279-Catch-22 and 715262-HPSuper). This work was also supported by Grants-in-Aid for Scientific Research (KAKENHI) and in Innovative Areas “Topological Material Science” (No. JP15H05852) and “Quantum Liquid Crystals” (No. JP19H05824) from the Japan Society for the Promotion of Science (JSPS) and by the Japan Science and Technology Agency (JST) CREST program (Grant No. JPMJCR19T5).
© 2022, The Author(s).