Quantum state discrimination circuits inspired by Deutschian closed timelike curves
Quantum state discrimination circuits inspired by Deutschian closed timelike curves
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DOI：
10.1103/physreva.105.052434
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发表时间：
2021-09
影响因子：
2.9
通讯作者：
Christopher Vairogs;Vishal Katariya;M. Wilde
中科院分区：
文献类型：
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作者：
Christopher Vairogs;Vishal Katariya;M. Wilde
众所周知，一方可以利用Deutschian封闭类时曲线（D-CTC）完美地区分多个非正交量子态。在本文中，我们提出了一个实用的方法来区分多个非正交态，通过使用以前已知的量子电路设计来模拟D-CTC。这种方法依赖于输入状态的多个副本，电路的多次迭代，以及一组固定的酉运算。我们首先描述该电路的性能，并研究其渐近行为。我们还展示了它如何可以等效地重铸为一个本地的，自适应电路，可以简单地在实验中实现。最后，我们证明了我们的状态鉴别策略在鉴别任意一组纯量子比特态时达到了多重Cherno界。
It is known that a party with access to a Deutschian closed timelike curve (D-CTC) can perfectly distinguish multiple non-orthogonal quantum states. In this paper, we propose a practical method for discriminating multiple non-orthogonal states, by using a previously known quantum circuit designed to simulate D-CTCs. This method relies on multiple copies of an input state, multiple iterations of the circuit, and a fixed set of unitary operations. We first characterize the performance of this circuit and study its asymptotic behavior. We also show how it can be equivalently recast as a local, adaptive circuit that may be implemented simply in an experiment. Finally, we prove that our state discrimination strategy achieves the multiple Chernoff bound when discriminating an arbitrary set of pure qubit states.