Quantum advantages for Pauli channel estimation
Quantum advantages for Pauli channel estimation
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DOI：
10.1103/physreva.105.032435
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发表时间：
2022-03-22
影响因子：
2.9
通讯作者：
Jiang, Liang
中科院分区：
文献类型：
--
作者：
Chen, Senrui;Zhou, Sisi;Jiang, Liang
我们发现，纠缠测量提供了一个指数的优势，在样本复杂性泡利信道估计，这是一个基本的问题和一个实际上重要的子程序基准近期量子设备。我们考虑的具体任务是同时学习n量子位泡利通道的所有本征值到+/-π精度。我们给出了一个估计协议与一个n-qubit的辅助，成功的概率很高，仅使用O（n/n（2））个副本的泡利通道，同时证明任何辅助协议（可能与自适应控制和信道级联）将需要至少欧米茄（2（n）（/3））轮的测量。我们进一步研究了少量的Ancillas所提供的优势。对于k量子比特附属（k
We show that entangled measurements provide an exponential advantage in sample complexity for Pauli channel estimation, which is both a fundamental problem and a practically important subroutine for benchmarking near-term quantum devices. The specific task we consider is to simultaneously learn all the eigenvalues of an n-qubit Pauli channel to +/-epsilon precision. We give an estimation protocol with an n-qubit ancilla that succeeds with high probability using only O(n/epsilon(2)) copies of the Pauli channel, while proving that any ancilla-free protocol (possibly with adaptive control and channel concatenation) would need at least Omega(2(n)(/3)) rounds of measurement. We further study the advantages provided by a small number of ancillas. For the case that a k-qubit ancilla (k