Momentum-resolved measurement of electronic nematic susceptibility in the FeSe0.9S0.1 superconductor

C. Cai; T. T. Han; Z. G. Wang; L. Chen; Y. D. Wang; Z. M. Xin; M. W. Ma; Yuan Li; Y. Zhang

doi:10.1103/PhysRevB.101.180501

← Back to search

Momentum-resolved measurement of electronic nematic susceptibility in the FeSe0.9S0.1 superconductor

C. Cai, T. T. Han, Z. G. Wang, L. Chen, Y. D. Wang, Z. M. Xin, M. W. Ma, Yuan Li, Y. Zhang

DOI 10.1103/PhysRevB.101.180501 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

Unveiling the driving force for a phase transition is normally difficult when multiple degrees of freedom are strongly coupled. One example is the nematic phase transition in iron-based superconductors. Its mechanism remains controversial due to a complex intertwining among different degrees of freedom. In this Rapid Communication, we report a method for measuring the nematic susceptibly of FeSe0.9S0.1 using angle-resolved photoemission spectroscopy and an in situ strain-tuning device. The nematic susceptibility is characterized as an energy shift of band induced by a tunable uniaxial strain. We found that the temperature dependence of the nematic susceptibility is strongly momentum dependent. As the temperature approaches the nematic transition temperature from the high temperature side, the nematic susceptibility remains weak at the Brillouin zone center while showing divergent behavior at the Brillouin zone corner. Our results highlight the complexity of the nematic order parameter in momentum space, which provides crucial clues to the driving mechanism of the nematic phase transition. Our experimental method which can directly probe the electronic susceptibly in momentum space provides a way to study the complex phase transitions in various materials.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
FeSe0.9S0.1 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
FeSe0.9S0.1 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
FeSe0.9S0.1 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown