Graphene quantum dots mimic orbital hybridization

The research team led by Professor Sun Qing-Feng, collaborated with Professor Lin’s research group at Beijing Normal University, to achieve orbital hybridization of graphene-based artificial atoms for the first time.

Their work, entitled “Orbital Hybridization in Graphene-Based Artificial Atoms,” has been published in nature. This work presents important milestones in the fields of quantum physics and materials science, filling in the gaps between artificial and actual atomic behavior.

Quantum dots, often called artificial atoms, can mimic atomic orbitals, but have yet to be used to simulate orbital hybridization, a key process of actual atoms. Quantum dots have successfully demonstrated artificial and anti-bonding states, but their ability to replicate orbital hybridization remained unexplored.

There was a lack of basic understanding of how anisotropic confinement affects quantum dot hybridization.

The authors have developed a theoretical framework and experimental approach to achieving orbital hybridization in graphene-based quantum dots. They proposed that anisotropic potentials of artificial atoms can induce hybridization between limited states of different orbitals, such as S-orbital (0 orbital quantum number) and D-orbital (2 orbital quantum number).

By deforming the circulating potential of the graphene quantum dots into an elliptical potential, the team successfully induced orbital hybridization, resulting in two hybridization states with different shapes (θ and rotary θ shapes).

Experimental results obtained by investigating confined states with various quantum dots confirm theoretical predictions and demonstrated the recombination of atomic decay states (quantum electrodynamic phenomenon) and whisper gallery modes (acoustic phenomenon).