Mobility analysis of FeTe thin films

TL;DR

This study examines the Hall effect in FeTe thin films, revealing how changes in hole and electron mobility relate to the emergence of superconductivity, highlighting the importance of itinerant charge carriers.

Contribution

It provides detailed analysis of charge carrier mobility and its suppression in FeTe thin films, linking it to the onset of superconductivity, which is a novel insight in iron chalcogenide research.

Findings

Hall coefficient sign reversal with temperature

Hole mobility is suppressed in the antiferromagnetic state

Superconductivity correlates with insufficient hole mobility suppression

Abstract

The Hall effect is investigated in detail for nonsuperconducting and superconducting FeTe thin films. The Hall coefficient commonly exhibits a sign reversal from positive in a high-temperature paramagnetic state to negative in a low-temperature antiferromagnetic state. Phenomenological analysis by a simple two-band Drude model indicates that hole mobility is significantly suppressed in the antiferromagnetic state. When suppression of the hole mobility is insufficient, superconductivity shows up in FeTe. This result strongly suggests that the itinerancy in both hole and electron channels is the essential factor for the occurrence of superconductivity in iron chalcogenide superconductors.