国防科技大学陈平形团队近日研究了高维捕获离子系统中统一耦合簇分析的高效实现。相关论文于2025年6月23日发表在《物理评论A》杂志上。

变分量子本征求解器（VQE）算法特别适合于估计噪声中尺度量子时代分子系统的基态能量。然而，最流行的幺正耦合簇模拟需要大量的量子位和门，这些量子位和门受到短相干时间和硬件噪声的限制。在这项研究中，课题组提出了使用高维方法在捕获离子系统中使用VQE算法估算分子H₂和LiH基态能量的方案。结果表明，实现与基于量子比特的模型相同的结果所需的量子门要少得多。 

高维量子模拟可以更好地利用量子资源。利用最近开发的固定输入状态方法，可以进一步减小电路的深度。分别只需要一个和三个单量子比特门来模拟H₂和LiH分子。最后，结合零噪声外推技术来减轻噪声的影响，结果的准确性得到了显著提高。这些发现表明，在高维量子模拟中使用固定的输入状态可以提高近期量子计算硬件的性能。

附：英文原文

Title: Efficient implementation of the unitary coupled-cluster ansatz in high-dimensional trapped-ion systems

Author: Peng Wang, Xueying Yang, Chun-Wang Wu, Chunyan Li, Wei Wu, Ping-Xing Chen

Issue&Volume: 2025/06/23

Abstract: The variational quantum eigensolver (VQE) algorithm is particularly well suited for estimating the ground-state energies of molecular systems in the noisy intermediate-scale quantum era. However, the most popular unitary coupled-cluster ansatz requires a large number of qubits and gates that are constrained by short coherence time and hardware noise. In this study, we present schemes for estimating the ground-state energies of the molecules H2 and LiH using the VQE algorithm in a trapped-ion system with a high-dimensional method. It is shown that significantly fewer quantum gates are required to achieve the same result as the qubit-based model. High-dimensional quantum simulation can make more use of quantum resources. Utilizing the recently developed fixed-input-state method, the depth of the circuits can be further reduced. Only one and three single-qubit gates are required for the simulation of the H2 and LiH molecules, respectively. Finally, combined with the zero-noise extrapolation technique to mitigate the effects of noise, the accuracy of the results is significantly improved. These findings indicate that using a fixed input state in high-dimensional quantum simulations can enhance the performance of near-term quantum computing hardware.

DOI: 10.1103/79nd-mr7f

Source: https://journals.aps.org/pra/abstract/10.1103/79nd-mr7f