Short-depth circuits and error mitigation for large-scale GHZ-state preparation, and benchmarking on IBM’s 127-qubit system

Published in 2023 IEEE International Conference on Quantum Computing and Engineering (QCE), 2023

This paper evaluates two IBM quantum devices—Eagle r3 (Sherbrooke, 127 qubits) and Falcon r8 (Peekskill, 27 qubits)—focusing on their ability to generate high-fidelity Greenberger–Horne–Zeilinger (GHZ) states. By introducing tree-based and centered-tree-based shallow-depth circuit constructions, the study significantly improves entanglement fidelity while mitigating hardware errors.

Key contributions include:

  • Depth-reduction strategies that exploit device topology to minimize two-qubit gate counts.
  • A comparative benchmark of Sherbrooke’s large-scale architecture versus Peekskill’s mid-scale layout.
  • Demonstration that higher qubit counts enable richer applications in quantum cryptography, measurement-based quantum computing, and quantum simulation.

These results establish a practical pathway for preparing entangled states on today’s NISQ hardware, laying the groundwork for more efficient and versatile future quantum systems.

Figure: Benchmarking different GHZ-state preparation approaches.

Recommended citation: Chen, Kuan-Cheng. (2023). "Short-depth circuits and error mitigation for large-scale GHZ-state preparation, and benchmarking on IBM's 127-qubit system." Proceedings of the 2023 IEEE International Conference on Quantum Computing and Engineering (QCE), 2, 207-210.
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