Du Fang-Fang, Ren Xue-Mei, Guo Jing
Opt Express. 2024 Aug 26;32(18):31633-31643. doi: 10.1364/OE.530004.
Quantum computing in high-dimensional spaces holds promise for a plethora of applications, i.e., handling more intricate information and executing wider quantum operations, in complex quantum information technologies (QITs). In the paper, we set up an error-heralded, resource-saving, circuit-simplified, and 4×4-dimensional controlled-not (CNOT) gate, where the polarized and spatial state of the flying photon (i.e., the control qudit) can effectively control the collective spin wave state of two atomic ensembles (i.e., the target qudit) in two double-sided cavities. Moreover, through meticulous analysis, the feasibility of the high-dimensional gate using existing technology boasts the exceptional performance including a near-unity fidelity and high efficiency exceeding 0.95, in principle, as the undesired performances originated from the little side leakage and the finite coupling strength, and the imperfect atom-ensemble-cavity interactions are heralded by single-photon detectors. Besides, auxiliary photons or atomic ensembles are unnecessary. Therefore, our protocol stands out for its simplicity, efficient resource utilization, and real-time error prediction, contributing significantly to the efficacy of QIT and charting a promising path towards the realization of high-dimensional quantum computing endowed with heightened capabilities.
高维空间中的量子计算在复杂量子信息技术（QITs）的众多应用中具有潜力，即处理更复杂的信息并执行更广泛的量子操作。在本文中，我们构建了一个具有错误预示、资源节省、电路简化的4×4维受控非门（CNOT），其中飞行光子（即控制量子位）的偏振和空间状态可以有效控制两个双面腔中两个原子系综（即目标量子位）的集体自旋波状态。此外，通过细致分析，利用现有技术实现高维门的可行性具有卓越性能，原则上包括接近单位的保真度和超过0.95的高效率，因为不期望的性能源于少量的边泄漏和有限的耦合强度，而单光子探测器预示着原子系综 - 腔相互作用的不完善。此外，不需要辅助光子或原子系综。因此，我们的协议因其简单性、高效的资源利用和实时错误预测而脱颖而出，对QIT的功效有显著贡献，并为实现具有更高能力的高维量子计算开辟了一条有前景的道路。
