The paper discusses the formation of spin qubits in graphene quantum dots, addressing the challenges and solutions for achieving long-distance coupling and reducing decoherence. The authors highlight that graphene, due to its weak spin-orbit coupling and absence of hyperfine interaction with nuclear spins, is an excellent candidate for qubit systems. They propose using graphene nanoribbons with armchair boundaries to lift the valley degeneracy, enabling Heisenberg exchange coupling between spins in tunnel-coupled quantum dots. The Klein paradox in graphene allows for long-distance coupling through conduction and valence band tunneling processes. The paper also provides detailed calculations of bound-state solutions and the exchange coupling strength, demonstrating that the system can support universal two-qubit gates and has potential for fault-tolerant quantum computation due to its low error rate and high error threshold.The paper discusses the formation of spin qubits in graphene quantum dots, addressing the challenges and solutions for achieving long-distance coupling and reducing decoherence. The authors highlight that graphene, due to its weak spin-orbit coupling and absence of hyperfine interaction with nuclear spins, is an excellent candidate for qubit systems. They propose using graphene nanoribbons with armchair boundaries to lift the valley degeneracy, enabling Heisenberg exchange coupling between spins in tunnel-coupled quantum dots. The Klein paradox in graphene allows for long-distance coupling through conduction and valence band tunneling processes. The paper also provides detailed calculations of bound-state solutions and the exchange coupling strength, demonstrating that the system can support universal two-qubit gates and has potential for fault-tolerant quantum computation due to its low error rate and high error threshold.