Overhead for simulating a non-local channel with local channels by quasiprobability sampling
Overhead for simulating a non-local channel with local channels by quasiprobability sampling
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DOI：
10.22331/q-2021-01-28-388
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发表时间：
2020-06
期刊：
影响因子：
6.4
通讯作者：
K. Mitarai;K. Fujii
中科院分区：
文献类型：
--
作者：
K. Mitarai;K. Fujii
随着量子计算硬件技术的进步，人们积极探索和开发其可能的应用。然而，这样的应用仍然受到量子设备上的噪声的影响，特别是当使用保真度相对较低的两个量子比特门时。克服这一困难的一种方法是用本地业务取代这种非本地业务。这种替换可以通过将非本地信道分解成本地信道的线性组合并用基于准概率的方法模拟原始信道来执行。在这项工作中，我们首先定义了一个量，我们称之为非局部性的信道稳健性，它量化了分解的代价。虽然对于一般的非局域信道，这个量的计算具有挑战性，但我们通过给出一个显式分解，给出了一般的两量子比特酉信道的上界。这种分解是通过推广我们以前的工作而得到的，它的应用被限制在某种形式的两量子位酉性上。这项工作开发了一个适用于第一代量子设备的资源减少框架。
As the hardware technology for quantum computing advances, its possible applications are actively searched and developed. However, such applications still suffer from the noise on quantum devices, in particular when using two-qubit gates whose fidelity is relatively low. One way to overcome this difficulty is to substitute such non-local operations by local ones. Such substitution can be performed by decomposing a non-local channel into a linear combination of local channels and simulating the original channel with a quasiprobability-based method. In this work, we first define a quantity that we call channel robustness of non-locality, which quantifies the cost for the decomposition. While this quantity is challenging to calculate for a general non-local channel, we give an upper bound for a general two-qubit unitary channel by providing an explicit decomposition. The decomposition is obtained by generalizing our previous work whose application has been restricted to a certain form of two-qubit unitary. This work develops a framework for a resource reduction suitable for first-generation quantum devices.