Multiband effects on beta-FeSe single crystals

TL;DR

This study investigates the multiband effects on the upper critical fields and Hall effect in beta-FeSe single crystals, revealing how pressure and magnetic field orientation influence superconducting and electronic properties.

Contribution

The paper provides new insights into the multiband nature of beta-FeSe, highlighting the impact of pressure and magnetic field orientation on its critical fields and carrier contributions.

Findings

Hc2(T) increases at lower temperatures for both field directions

Anisotropy and Hc2(T) increase under pressure

Hole carriers dominate at high fields, electrons at low fields and temperatures

Abstract

We present the upper critical fields Hc2(T) and Hall effect in beta-FeSe single crystals. The Hc2(T) increases as the temperature is lowered for field applied parallel and perpendicular to (101), the natural growth facet of the crystal. The Hc2(T) for both field directions and the anisotropy at low temperature increase under pressure. Hole carriers are dominant at high magnetic fields. However, the contribution of electron-type carriers is significant at low fields and low temperature. Our results show that multiband effects dominate Hc2(T) and electronic transport in the normal state.