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arXiv quant-ph/0407054quant-phcs.ET
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通过正交测量实现群协变 POVM

Implementation of group-covariant POVMs by orthogonal measurements

Thomas Decker, Dominik Janzing, Martin Roetteler

AI总结:

本文基于对称群的表示理论,提出利用矩阵分解方法实现由秩一算子构成的群协变 POVM 的量子电路,并给出了由 Weyl-Heisenberg 群生成的高效量子电路示例,实现了粒子位置与晶体动量的近似同时测量。

摘要:

我们考虑有限维量子系统上的群协变正定算子值测量(POVM)。根据 Neumark 定理,POVM 可通过在更大系统上的正交测量来实现。因此,我们的目标是利用对称性,寻找给定群协变 POVM 的量子电路实现。基于对称群的表示理论,我们开发了一种实现由秩一算子构成的群协变 POVM 的通用方法。该构造依赖于一种分解矩阵的方法,这些矩阵将有限群的两个表示交织在一起。我们给出了几个示例,其生成的量子电路是高效的。特别是,对于由 Weyl-Heisenberg 群生成的一类 POVM,我们获得了高效的量子电路。这些电路能够实现对沿循环链运动的粒子的位置和晶体动量的近似同时测量。

英文摘要:

We consider group-covariant positive operator valued measures (POVMs) on a finite dimensional quantum system. Following Neumark's theorem a POVM can be implemented by an orthogonal measurement on a larger system. Accordingly, our goal is to find an implementation of a given group-covariant POVM by a quantum circuit using its symmetry. Based on representation theory of the symmetry group we develop a general approach for the implementation of group-covariant POVMs which consist of rank-one operators. The construction relies on a method to decompose matrices that intertwine two representations of a finite group. We give several examples for which the resulting quantum circuits are efficient. In particular, we obtain efficient quantum circuits for a class of POVMs generated by Weyl-Heisenberg groups. These circuits allow to implement an approximative simultaneous measurement of the position and crystal momentum of a particle moving on a cyclic chain.

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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