We report on finite bias spectroscopy measurements of the two-electron spectrum in a gate defined bilayer graphene (BLG) quantum dot for varying magnetic fields. The spin and valley degree of freedom in BLG give rise to multiplets of 6 orbital symmetric and 10 orbital anti-symmetric states.
We find that orbital symmetric states are lower in energy and separated by ≈ 0.4 − 0.8 meV from orbital anti-symmetric states. The symmetric multiplet exhibits an additional energy splitting of its 6 states of ≈ 0.15 − 0.5 meV due to lattice scale interactions. The experimental observations are supported by theoretical calculations, which allow to determine that inter-valley scattering and
’current-current’ interaction constants are of the same magnitude in BLG