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arXiv 1002.3780quant-ph
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有效重构量子态

Reconstructing quantum states efficiently

M. Cramer, M. B. Plenio

摘要:

量子态层析成像是一种从测量数据中推导出量子系统的密度矩阵的方法,它对于当前和未来量子器件的验证具有重要意义。它已经在具有很少组件的系统中实现,但是对于较大的系统,它迅速变得不可行,因为量子测量的数量和处理它们所需的计算资源在系统大小中呈指数增长。在这里,我们表明,我们可以获得一个指数的优势,直接状态层析成像的量子态通常实现的性质。基于奇异值阈值和矩阵乘积状态方法,我们引入了一个状态重建方案,只依赖于一个线性数量的测量。用于从这些测量以高保真度重建状态所需的后处理的计算资源在系统大小上是多项式的。

英文摘要:

Quantum state tomography, the ability to deduce the density matrix of a quantum system from measured data, is of fundamental importance for the verification of present and future quantum devices. It has been realized in systems with few components but for larger systems it becomes rapidly infeasible because the number of quantum measurements and computational resources required to process them grow exponentially in the system size. Here we show that we can gain an exponential advantage over direct state tomography for quantum states typically realized in nature. Based on singular value thresholding and matrix product state methods we introduce a state reconstruction scheme that relies only on a linear number of measurements. The computational resources for the postprocessing required to reconstruct the state with high fidelity from these measurements is polynomial in the system size.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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