Spin and Valley States in Gate-defined Bilayer Graphene Quantum Dots

In bilayer graphene, electrostatic confinement can be realized by a suitable design of top and back gate electrodes. We measure electronic transport through a bilayer graphene quantum dot, which is laterally confined by gapped regions and connected to the leads via p-n junctions. Single electron and hole occupancy is realized and charge carriers $n=1,2,\dots 50$ can be filled successively into the quantum system with charging energies exceeding $10
$\mathrm{m}\mathrm{e}\mathrm{V}$$. For the lowest quantum states, we can clearly observe valley and Zeeman splittings with a spin g-factor of $g_s\approx 2$. In the low field-limit, the valley splitting depends linearly on the perpendicular magnetic field and is in qualitative agreement with calculations.