Abstract

We report the evolution of electrical transport properties in insulating FeSe films with electron doping induced by the ionic liquid gating technique. Superconductivity never emerges in the strong insulators with variable-range hopping behavior but is shown to arise once the resistance of the normal state varies as $ln(1/T)$, indicating that this behavior corresponds to the minimal conducting character for developing superconductivity. Our work points toward granular metallicity for the $ln(1/T)$ behavior, suggesting that the emergence of superconductivity requires at least an insulating state containing metallic granules. Moreover, it unravels an electronic segregation in proximity to superconductor-insulator transition, which calls for a comprehensive understanding of this segregated phase.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.