Signatures of a Quantum Griffiths Phase close to an Electronic Nematic Quantum Phase Transition

Abstract

In the vicinity of a quantum critical point, quenched disorder can lead to a quantum Griffiths phase, accompanied by an exotic power-law scaling with a continuously varying dynamical exponent that diverges in the zero-temperature limit. Here, we investigate a nematic quantum critical point in the iron-based superconductor FeSe${}_{0.89}$S${}_{0.11}$ using applied hydrostatic pressure. We report an unusual crossing of the magnetoresistivity isotherms in the non-superconducting normal state which features a continuously varying dynamical exponent over a large temperature range. We interpret our results in terms of a quantum Griffiths phase caused by nematic islands that result from the local distribution of Se and S atoms. At low temperatures, the Griffiths phase is masked by the emergence of a Fermi liquid phase due to a strong nematoelastic coupling and a Lifshitz transition that changes the topology of the Fermi surface.

6 pages, 4 figures

References in corpus (9)

• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• Anomalous Fermi surface in FeSe seen by Shubnikov-de Haas oscillation measurements
• Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment
• Suppression of electronic correlations by chemical pressure from FeSe to FeS
• Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La${}_{2-x}$Sr${}_x$CuO${}_4$
• Scattering mechanisms and electrical transport near an Ising nematic quantum critical point
• Strain-tuning of nematicity and superconductivity in single crystals of FeSe
• Infinite randomness fixed point of the superconductor-metal quantum phase transition
• Visualizing nematic transition and nanoscale suppression of superconductivity in Fe(Te,Se)

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