Competition between superconductivity and magnetic/nematic order as a source of anisotropic superconducting gap in underdoped Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$

H. Kim, M. A. Tanatar, W. E. Straszheim +8

The in-plane London penetration depth, $\Delta \lambda (T)$, was measured using a tunnel diode resonator technique in single crystals of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ with doping levels $x$…