Multiorbital effects on the transport and the superconducting fluctuations in LiFeAs

TL;DR

This study investigates multiorbital effects on transport and superconducting fluctuations in LiFeAs, revealing a multiband contribution to transport, Fermi liquid behavior, and quasi-2D superconducting fluctuations persisting above Tc.

Contribution

It provides detailed experimental insights into multiband transport and fluctuation behavior in LiFeAs, highlighting the need for refined theories of multiband superconductivity.

Findings

Four carrier bands contribute to transport.

All carriers exhibit T^2 scattering rates.

Superconducting fluctuations are quasi-2D and persist up to 1.4 Tc.

Abstract

The resistivity, Hall effect and transverse magnetoresistance (MR) have been measured in low residual resistivity single crystals of LiFeAs. A comparison with angle resolved photoemission spectroscopy and quantum oscillation data implies that four carrier bands unevenly contribute to the transport. However the scattering rates of the carriers all display the T^2 behavior expected for a Fermi liquid. Near Tc low field deviations of the MR with respect to a H^2 variation permit us to extract the superconducting fluctuation contribution to the conductivity. Though below Tc the anisotropy of superconductivity is rather small, the superconducting fluctuations display a quasi ideal two-dimensional behavior which persists up to 1.4 Tc. These results call for a refined theoretical understanding of the multiband behavior of superconductivity in this pnictide.