2019 EJRNL PP A. KURZMANN 1.pdf
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Terbatas Ratnasari
» ITB
Terbatas Ratnasari
» ITB
We report ground- and excited-state transport through an electrostatically defined few-hole quantum dot
in bilayer graphene in both parallel and perpendicular applied magnetic fields. A remarkably clear level
scheme for the two-particle spectra is found by analyzing finite bias spectroscopy data within a two-particle
model including spin and valley degrees of freedom. We identify the two-hole ground state to be a spintriplet and valley-singlet state. This spin alignment can be seen as Hund’s rule for a valley-degenerate
system, which is fundamentally different from quantum dots in carbon nanotubes, where the two-particle
ground state is a spin-singlet state. The spin-singlet excited states are found to be valley-triplet states by
tilting the magnetic field with respect to the sample plane.We quantify the exchange energy to be 0.35 meV
and measure a valley and spin g factor of 36 and 2, respectively.