The tightness of multipartite coherence from spectrum estimation [article]

Qi-Ming Ding, Xiao-Xu Fang, He Lu
2021 arXiv   pre-print
Detecting multipartite quantum coherence usually requires quantum state reconstruction, which is quite inefficient for large-scale quantum systems. Along this line of research, several efficient procedures have been proposed to detect multipartite quantum coherence without quantum state reconstruction, among which the spectrum-estimation-based method is suitable for various coherence measures. Here, we first generalize the spectrum-estimation-based method for the geometric measure of coherence.
more » ... Then, we investigate the tightness of the estimated lower bound of various coherence measures, including the geometric measure of coherence, l_1-norm of coherence, the robustness of coherence, and some convex roof quantifiers of coherence multiqubit GHZ states and linear cluster states. Finally, we demonstrate the spectrum-estimation-based method as well as the other two efficient methods by using the same experimental data [Ding et al. Phys. Rev. Research 3, 023228 (2021)]. We observe that the spectrum-estimation-based method outperforms other methods in various coherence measures, which significantly enhances the accuracy of estimation.
arXiv:2104.12094v2 fatcat:hl6p6ktrqfbgxn3szv32sj4ohq