Physics – Condensed Matter – Superconductivity
Scientific paper
2012-01-13
Physics
Condensed Matter
Superconductivity
Scientific paper
The London penetration depth was measured in single crystals of self-doped Na$_{1-\delta}$FeAs (under- to optimal doping, $T_c$ from 14 to 27 K) and electron-doped Na(Fe$_{1-x}$Co$_{x}$)As with $x$ ranging from 0 to 0.1 (from underdoped to overdoped compositions). In all samples, the low - temperature variation of the penetration depth exhibits a power-law dependence, $\Delta \lambda (T) = AT^n$, with the exponent $n$ as low as $n = 1.1$, which is close to the value expected for a superconducting gap with line nodes. Moreover, even at the optimal doping, the results are incompatible with fully-gapped superconductivity. The full - temperature range superfluid density, $\rho_s(T) = (\lambda(0)/\lambda(T))^2$, is distinctly different from other charge - doped pnictides and is similar to isovalently - substituted BaFe$_2$(As$_{1-x}$P$_x$)$_2$, believed to be a nodal pnictide at the optimal doping. This result breaks the monopoly of isovalently - substituted materials for nodal superconductivity in optimally doped Fe-based superconductors, and is against a recent suggestion that the pnictrogen height controls nodal vs. nodeless structure of the superconducting gap.
Cho Kihyeon
Dai Pengcheng
Kim Hungsoo
Prozorov Ruslan
Spyrison N.
No associations
LandOfFree
Nodal superconducting gap in optimally charge-doped Na$_{1-δ}$(Fe$_{1-x}$Co$_x$)As does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nodal superconducting gap in optimally charge-doped Na$_{1-δ}$(Fe$_{1-x}$Co$_x$)As, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nodal superconducting gap in optimally charge-doped Na$_{1-δ}$(Fe$_{1-x}$Co$_x$)As will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-693360