Adaptive Protocol for R\'enyi Entropy Estimation

arXiv:2611.10330v1 Announce Type: new Abstract: The second-order R\'enyi entropy is one of the most important quantities used for characterizing the entanglement structure of states prepared in quantum many-body experiments. With access to qubit projective measurement data, it can be estimated via a protocol in which repeated measurements are taken after each of a set of random local unitary operations is applied to the quantum state. To obtain accurate values for the second R\'enyi entropy on shot-limited devices, care must be taken when choosing the number of different unitary settings to apply, and the respective number of projective measurements to take.