arXiv subjects

Ann S. Erickson

Publications and source records attributed to Ann S. Erickson.

2 recordsLinked to original sources

arXiv2009

Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry

We measure changes in the penetration depth $λ$ of the $T_c \approx 6$ K superconductor LaFePO. In the process scanning SQUID susceptometry is demonstrated as a technique for accurately measuring {\it local} temperature-dependent changes in $λ$, making it ideal for studying early or difficult-to-grow materials. $λ$ of LaFePO is found to vary linearly with temperature from 0.36 to $\sim$2 K, with a slope of 143$\pm$15 Å/K, suggesting line nodes in the superconducting order parameter. The linear dependence up to $\sim T_c/3$ is similar to the cuprate superconductors, indicating well-developed nodes.

cond-mat.supr-con↗

arXiv2008

Bulk superconductivity and disorder in single crystals of LaFePO

We have studied the intrinsic normal and superconducting properties of the oxypnictide LaFePO. These samples exhibit bulk superconductivity and the evidence suggests that stoichiometric LaFePO is indeed superconducting, in contrast to other reports. We find that superconductivity is independent of the interplane residual resistivity $ρ_0$ and discuss the implications of this on the nature of the superconducting order parameter. Finally we find that, unlike $T_c$, other properties in single-crystal LaFePO including the resistivity and magnetoresistance, can be very sensitive to disorder.

cond-mat.supr-con↗