Spin splitting in graphene studied by means of tilted magnetic-field experiments

We have measured the spin splitting in single-layer and bilayer graphene by means of tilted magnetic-field experiments. By applying the Lifshitz-Kosevich formula for the spin-induced decrease of the Shubnikov-de Haas amplitudes with increasing tilt angle, we directly determine the product between the carrier cyclotron mass ${m}^{*}$ and the effective $g$ factor ${g}^{*}$ as a function of the charge-carrier concentration. By using the cyclotron mass for a single-layer and a bilayer graphene, we find an enhanced $g$ factor ${g}^{*}=2.7\ifmmode\pm\else\textpm\fi{}0.2$ for both systems.