De Haas-van Alphen Oscillations in KFe$_2$As$_2$

In order to clarify pairing mechanisms and symmetries of the new high-$T_c$ superconductivity in the FeAs compounds, it is necessary to know their Fermi surfaces. We report on de Haas-van Alphen effect in KFe$_2$As$_2$, which is an end member of the high-$T_c$ binary alloy (Ba, K)Fe$_2$As$_2$. It shows no magnetic or structural phase transition down to low temperatures and becomes superconducting below about 3 K. We have observed many dHvA frequencies and their angular dependences are basically 1/cos$\theta$, where $\theta$ is the angle between the $c$ axis and the magnetic field. At the moment, our analysis indicates that three quasi-two-dimensional FS cylinders have been observed and that they occupy about 1, 8, and 12\% of the Brillouin zone, respectively. The effective masses of electrons are fairly heavy, ranging from 6 to 9 times the free electron mass for $B \parallel c$. This seems consistent with previously reported $T^2$ dependence of $\rho$ with a large $A$ coefficient [1] and large Sommerfeld coefficient of the specific heat [2]. [1] T. Terashima \textit{et al}., JPSJ 78, 063702 (2009). [2] H. Fukazawa \textit{et al}., JPSJ 78, 083712 (2009).