Necessity of the entropy-dependent term in the single-copy model

Determine whether the entropy-dependent term in the sample-complexity upper bound for single-copy estimation of the state frame potential is necessary.

Background

In the single-copy sample model, the paper gives a store-and-estimate algorithm whose sample complexity depends on a Rényi entropy of the ensemble-weight distribution. The paper does not establish a matching lower bound for this entropy-dependent contribution and explicitly poses its necessity as an open problem.

References

For the single-copy model, an important open problem is to determine whether the entropy-dependent term is necessary.

Towards Optimal Quantum Estimators for State Frame Potential  (2608.24711 - Bao et al., 25 Aug 2026) in Section 6, Discussion

Establishing a distribution-free guarantee for such a preliminary stage is left for future work.

Towards Optimal Quantum Estimators for State Frame Potential  (2608.24711 - Bao et al., 25 Aug 2026) in Section 2.3, Single-copy sample model