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 FeSe0.89S0.11 using applied hydrostatic pressure. We report an unusual crossing of the magneto resistivity isotherms in the Non superconducting normal state that 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 Nemat elastic coupling and a Lifshitz transition that changes the topology of the Fermi surface.

Department(s)

Physics

Comments

National Science Foundation, Grant EP/M020517/1

International Standard Serial Number (ISSN)

1079-7114; 0031-9007

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Physical Society, All rights reserved.

Publication Date

10 Dec 2021

PubMed ID

34951778

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