arXiv subjects

Alon Yagil

Publications and source records attributed to Alon Yagil.

2 recordsLinked to original sources

arXiv2018

Dependence of the absolute value of the penetration depth in $\mathrm{\mathbf{{(Ba_{1-x}K_x)Fe_2As_2}}}$ on doping

We report magnetic force microscopy (MFM) measurements on the iron-based superconductor $\mathrm{Ba_{1-x}K_xFe_2As_2}$. By measuring locally the Meissner repulsion with the magnetic MFM tip, we determine the absolute value of the in-plane magnetic penetration depth ($λ_{ab}$) in underdoped, optimally-doped, and overdoped samples. The results suggest an abrupt increase of $λ_{ab}$ as doping is increased from $x_\mathrm{opt}$, which is potentially related to the presence of a quantum critical point. The response of superconducting vortices to magnetic forces exerted by the MFM tip for $x=0.19$ and $0.58$ is compatible with previously observed structural symmetries at those doping levels.

cond-mat.supr-con↗

arXiv2014

Local characterization of superconductivity in BaFe2(As1-xPx)2

We use magnetic force microscopy (MFM) to characterize superconductivity across the superconducting dome in ${\rm {BaFe}_2 \left(As_{1-x}P_x\right)_2}$, a pnictide with a peak in the penetration depth ($λ_{ab}$) at optimal doping ($\rm x_{opt}$), as shown in sample-wide measurements. Our local measurements show a peak at $\rm x_{opt}$ and a $T_C$ vs. $λ_{ab}^{-2}$ dependence similar on both sides of $\rm x_{opt}$. Near the underdoped edge of the dome $λ_{ab}$ increases sharply suggesting that superconductivity competes with another phase. Indeed MFM vortex imaging shows correlated defects parallel to twin boundaries only in underdoped samples and not for $\rm x\ge x_{opt}$.

cond-mat.supr-con↗