Towards Distributed Quantum Error Correction for Distributed Quantum Computing

Quantum computing as a promising technology can utilize stochastic solutions instead of deterministic approaches for complicated scenarios for which classical computing is inefficient, provided that both the concerns of the error-prone nature of qubits and the limitation of the number of qubits are addressed carefully. In order to address both concerns, a new qubit-based Distributed Quantum Error Correction (DQEC) architecture is proposed in which three physical qubits residing on three Quantum Processing Units (QPU) are used to form a logical qubit. This paper illustrates how three QPUs collaboratively generate a joint quantum state in which single bit-flip and phase-flip errors can be properly resolved. By reducing the number of qubits required to form a logical qubit in the proposed architecture, each QPU with its limited number of physical qubits can accommodate more logical qubits than when it has to devote its three physical qubits for each logical qubit. The functional correctness of the proposed architecture is evaluated through the Qiskit tool and stabilizer generators. Moreover, the fidelity of input and output quantum states, the complexity of the proposed designs, and the dependency between error probability and correctness of the proposed architecture are analyzed to prove its effectiveness.