Trapped neutral atoms have become a prominent platform for quantum science, where entanglement fidelity records have been set using highly excited Rydberg states. However, controlled two-qubit entanglement generation has so far been limited to alkali species, leaving the exploitation of more complex electronic structures as an open frontier that could lead to improved fidelities and fundamentally different applications such as quantum-enhanced optical clocks. Here, we demonstrate a novel approach utilizing the two-valence electron structure of individual alkaline-earth Rydberg atoms. We find fidelities for Rydberg state detection, single-atom Rabi operations and two-atom entanglement that surpass previously published values. Our results pave the way for novel applications, including programmable quantum metrology and hybrid atom–ion systems, and set the stage for alkaline-earth based quantum computing architectures.

被困的中性原子已经成为量子科学的重要平台，其中纠缠保真度记录是使用高度激发的里德堡态来设定的。但是，迄今为止，受控的两量子位纠缠生成仅限于碱物种，而将更复杂的电子结构作为开放的前沿来开发，可能会导致保真度提高和根本上不同的应用，例如量子增强型光钟。在这里，我们演示了利用单个碱土里德堡原子的二价电子结构的新颖方法。我们发现Rydberg状态检测，单原子Rabi运算和两个原子纠缠的保真度超过了先前发表的值。我们的结果为新颖的应用铺平了道路，包括可编程量子计量学和混合原子离子系统，