ARPES observation of non-Fermi liquid behavior in hole-doped LiFe$_{1-x}$V$_x$As and electron-doped LiFe$_{1-x}$Co$_x$As superconductors
ORAL
Abstract
As with other Fe-based superconductors, the Fermi surface of LiFeAs is composed of multiple hole and electron Fermi surface pockets mainly derived from $3d_{xy}$, $3d_{yz}$ and $3d_{xz}$ orbitals. With its direct momentum resolution, ARPES is a powerful technique able to track the evolution of the Fermi surface upon doing. Here we reveal a non-Fermi liquid behavior in both Co-doped (electron) and V-doped (hole) LiFeAs characterized by a sub-square temperature dependence of the electrical resistivity. We show that for both types of carrier doping, the less Fermi liquid like behavior coincides with good Fermi nesting conditions between a hole and an electron Fermi surface pockets with different orbital characters that are separated by the ``antiferromagnetic" wave vector $\Gamma$-M. Our results suggest that the non-Fermi liquid behavior is driven by low-energy inter-orbital antiferromagnetic fluctuations, but that this observation is not correlated with superconductivity.
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