Graphene quantum dots and qubits
WEI Peng
GE Xiao-zhen
LI Na
XI Zai-rong
Abstract：This paper reviews the progress of preparation of graphene quantum dots (GQD) and the operation of spin qubits and charge qubits based on GQD. Since the graphene material has a relatively light atomic weight resulting to a smaller spin orbital interaction, and the 13C of carbon isotope containing the nuclear spin accounts for only about 1％in the nature world, the ultra-fine interaction (i.e., nuclear spin and electron spin interaction) is weaker, which means graphene has longer spin decoherence time than other materials. Therefore, graphene has promising application in quantum computation and quantum information. This paper calculates five different types of graphene quantum dots prepared by electrostatic confinement: 1) graphene nanoribbons with armchair, 2) a disc in monolayer graphene, 3) a disc in bilayer graphene, 4) a disc in trilayer graphene of ABC stacking, 5) a disc in trilayer graphene of ABA stacking. The key to application of spin qubits in the graphene quantum dots is the destruction of valley degeneracy. In the first scenario, boundary condition is used to destroy valley degeneracy, while in other cases, valley degeneracy is destroyed by external magnetic field. Further, the effect of spin-orbit interaction and hyperfine interaction on operation of spin is introduced in graphene quantum dots.
Keywords：graphene quantum dotspin qubitcharge qubitdecoherence
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 1437-1445 )