All Abstracts | Poster Abstracts | Talk Abstracts

Minimax quantum tomography: the ultimate bounds on accuracy

Chris Ferrie, Center for Quantum Information and Control, University of New Mexico

(Session 7a : Friday from 4:30 - 5:00)

Abstract. There are many methods for quantum state tomography (e.g., linear inversion, maximum likelihood, Bayesian mean...). But none of them is clearly "the most accurate" for data of finite size N. Even the upper limits on accuracy are as yet unknown, which makes it difficult to say that a given method is "accurate enough". We address this problem here by (i) calculating the minimum achievable error for single-qubit tomography with N Pauli measurements, (ii) finding "minimax" estimators that achieve this bound, and (iii) comparing the performance of known estimators.