Quasi-Two-Dimensional Fermi Surfaces and Coherent Interlayer Transport in KFe2As2

We report the results of the angular-dependent magnetoresistance oscillations (AMROs), which can determine the shape of bulk Fermi surfaces (FSs) in quasi-two-dimensional (Q2D) systems, in a highly hole-doped Fe-based superconductor ${\mathrm{KFe}}_{2}{\mathrm{As}}_{2}$ with ${T}_{c}\ensuremath{\approx}3.7\text{ }\text{ }\mathrm{K}$. From the AMROs, we determined the two Q2D FSs with rounded-square cross sections, correspond to 12% and 17% of the first Brillouin zone. The rounded-squared shape of the FS cross section is also confirmed by the analyses of the interlayer transport under in-plane fields. From the obtained FS shape, we infer the character of the $3d$ orbitals that contribute to the FSs.