文章基本信息

标题：A Compressed Classical Description of Quantum States
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作者：David Gosset ; John Smolin
期刊名称：LIPIcs : Leibniz International Proceedings in Informatics
电子版ISSN：1868-8969
出版年度：2019
卷号：135
页码：8:1-8:9
DOI：10.4230/LIPIcs.TQC.2019.8
出版社：Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
摘要：We show how to approximately represent a quantum state using the square root of the usual amount of classical memory. The classical representation of an n-qubit state psi consists of its inner products with O(sqrt{2^n}) stabilizer states. A quantum state initially specified by its 2^n entries in the computational basis can be compressed to this form in time O(2^n poly(n)), and, subsequently, the compressed description can be used to additively approximate the expectation value of an arbitrary observable. Our compression scheme directly gives a new protocol for the vector in subspace problem with randomized one-way communication complexity that matches (up to polylogarithmic factors) the optimal upper bound, due to Raz. We obtain an exponential improvement over Raz's protocol in terms of computational efficiency.
关键词：Quantum computation; Quantum communication complexity; Classical simulation