近日，澳大利亚悉尼大学Tan, T. R.团队实现了为Gottesman-Kitaev-Preskill逻辑量子比特设置的通用量子门。相关论文于2025年8月21日发表在《自然—物理学》杂志上。
创建大规模、容错量子计算机的传统方法需要一种纠错方案，该方案将多个物理量子比特主题化，以编码一个受保护量子信息的逻辑量子比特。实现纠错量子信息处理的一个关键限制因素是许多纠错码所需的物理与逻辑量子比特的大比例，超过了近期设备的尺寸。Gottesman-Kitaev-Preskill （GKP）编码通过将逻辑量子位元编码到单个量子谐振子中，以增加编码复杂性为代价提供了硬件效率。
在早期GKP编码操作演示的基础上，研究组实现了GKP逻辑量子比特上的纠缠门。他们的实验主题是一种最优控制策略，该策略确定地在捕获离子的机械运动中编码的有限能量GKP状态上实现一组通用的能量守恒逻辑门。研究组也直接从真空开始生成GKP贝尔态。他们的方法与现有的硬件架构兼容，展示了具有先进编码方案的最优控制技术的潜力，以加速大规模容错量子信息处理的道路。
附：英文原文
Title: Universal quantum gate set for Gottesman–Kitaev–Preskill logical qubits
Author: Matsos, V. G., Valahu, C. H., Millican, M. J., Navickas, T., Kolesnikow, X. C., Biercuk, M. J., Tan, T. R.
Issue&Volume: 2025-08-21
Abstract: Conventional approaches towards creating a large-scale, fault-tolerant quantum computer require an error correction scheme that uses multiple physical qubits to encode one logical qubit of protected quantum information. A key limiting factor in realizing error-corrected quantum information processing is the large ratio of physical-to-logical qubits required by many error correction codes, outstripping the size of near-term devices. The Gottesman–Kitaev–Preskill (GKP) code offers hardware efficiency at the cost of increased encoding complexity by encoding a logical qubit into a single quantum harmonic oscillator. Building on earlier demonstrations of GKP-encoded operations, we realize an entangling gate on GKP logical qubits. Our experiments use an optimal control strategy that deterministically implements a universal set of energy-preserving logical gates on finite-energy GKP states encoded in the mechanical motions of a trapped ion. We also directly generate a GKP Bell state starting from vacuum. Our approach is compatible with existing hardware architectures, demonstrating the potential for optimal control techniques with advanced encoding schemes to accelerate the path towards large-scale fault-tolerant quantum information processing.
DOI: 10.1038/s41567-025-03002-8
Source: https://www.nature.com/articles/s41567-025-03002-8