Efficient Fidelity Estimation of General Quantum Resource States via Clifford Circuits
Abstract
Fidelity estimation is a fundamental tool for assessing quantum resource states across quantum information science. For small infidelity ε, tomography and direct fidelity estimation (DFE) have worst-case sample complexity O(1/ε2) at fixed relative accuracy and confidence. Direct target projections achieve O(1/ε) but generally require non-Clifford operations whose reliability depends on the resource states that are typically the target of benchmarking. Here, we introduce the Bell--coherence fidelity estimation (BCFE) with optimal sample complexity Θ(1/ε) using only Clifford gates and Pauli measurements. We prove that BCFE is applicable to arbitrary pure targets, possibly multi-qubit, with the statistical error of the single-copy coherence part explicitly controlled. To evaluate BCFE in a practical setting, we apply BCFE to analog rotation resource states in the candidate early-FTQC architecture called the Space-Time Efficient Analog Rotations (STAR) architecture. In the simulations using surface codes, BCFE is estimated to require up to approximately $27$ times fewer resource states than DFE for the same standard error in the infidelity estimate, while its estimates remain close to reference values despite circuit-level noise in the additional Bell measurement operations. These results support efficient resource benchmarking within fault-tolerant quantum computing.
Related
- Efficient fidelity simulation of high-rate magic distillation circuits
- Efficient expectation value estimation for quantum circuits via extended stabilizer frameworks and adaptive variance estimation
- Exact verification of Givens rotation circuits for efficient quantum phase estimation of iron-sulfur clusters
- Universal purification dynamics of monitored Clifford circuits
- Clifford and Haar scramblers yield equal mean fidelity but unequal fluctuations in black hole-inspired teleportation
BibTeX
@misc{takahashi2026efficient,
title = {{Efficient Fidelity Estimation of General Quantum Resource States via Clifford Circuits}},
author = {Shunta Takahashi and Keisuke Fujii},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.05222},
eprint = {2610.05222},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.05222},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Efficient Fidelity Estimation of General Quantum Resource States via Clifford Circuits
AU - Shunta Takahashi
AU - Keisuke Fujii
PY - 2026
DA - 2026/10/04
PB - arXiv
DO - 10.48550/arxiv.2610.05222
UR - https://arxiv.org/abs/2610.05222
AB - Fidelity estimation is a fundamental tool for assessing quantum resource states across quantum information science. For small infidelity ε, tomography and direct fidelity estimation (DFE) have worst-case sample complexity O(1/ε^2) at fixed relative accuracy and confidence. Direct target projections achieve O(1/ε) but generally require non-Clifford operations whose reliability depends on the resource states that are typically the target of benchmarking. Here, we introduce the Bell--coherence fidelity estimation (BCFE) with optimal sample complexity Θ(1/ε) using only Clifford gates and Pauli measurements. We prove that BCFE is applicable to arbitrary pure targets, possibly multi-qubit, with the statistical error of the single-copy coherence part explicitly controlled. To evaluate BCFE in a practical setting, we apply BCFE to analog rotation resource states in the candidate early-FTQC architecture called the Space-Time Efficient Analog Rotations (STAR) architecture. In the simulations using surface codes, BCFE is estimated to require up to approximately $27$ times fewer resource states than DFE for the same standard error in the infidelity estimate, while its estimates remain close to reference values despite circuit-level noise in the additional Bell measurement operations. These results support efficient resource benchmarking within fault-tolerant quantum computing.
ER -