OPTIMAL LARGE-SCALE QUANTUM STATE TOMOGRAPHY WITH PAULI MEASUREMENTS

• 成果类型: Article
• 署名作者: Cai, Tony; Kim, Donggyu; Wang, Yazhen; Yuan, Ming; Zhou, Harrison H.
• 署名单位: University of Pennsylvania; University of Wisconsin System; University of Wisconsin Madison; Yale University
• 刊物名称: ANNALS OF STATISTICS
• ISSN/ISSBN: 0090-5364
• DOI: 10.1214/15-AOS1382
• 发表日期: 2016
• 页码: 682-712
• 关键词: low-rank matrices; homodyne tomography; wigner function; Optimal Rates; Minimax; Penalization; CONVERGENCE; computation; estimators; selection

摘要

Quantum state tomography aims to determine the state of a quantum system as represented by a density matrix. It is a fundamental task in modern scientific studies involving quantum systems. In this paper, we study estimation of high-dimensional density matrices based on Pauli measurements. In particular, under appropriate notion of sparsity, we establish the minimax optimal rates of convergence for estimation of the density matrix under both the spectral and Frobenius norm losses; and show how these rates can be achieved by a common thresholding approach. Numerical performance of the proposed estimator is also investigated.