The coherent control of interacting spins in semiconductor quantum dots is of strong interest for quantum information processing and for studying quantum magnetism from the bottom up. Here we present a 2 × 4 germanium quantum dot array with full and controllable interactions between nearest-neighbour spins. As a demonstration of the level of control, we define four singlet–triplet qubits in this system and show two-axis single-qubit control of each qubit and SWAP-style two-qubit gates between all neighbouring qubit pairs, yielding average single-qubit gate fidelities of 99.49(8)–99.84(1)% and Bell state fidelities of 73(1)–90(1)%. Combining these operations, we experimentally implement a circuit designed to generate and distribute entanglement across the array. A remote Bell state with a fidelity of 75(2)% and concurrence of 22(4)% is achieved. These results highlight the potential of singlet–triplet qubits as a competing platform for quantum computing and indicate that scaling up the control of quantum dot spins in extended bilinear arrays can be feasible.

半导体量子点中相互作用自旋的相干控制对于量子信息处理和自下而上研究量子磁性具有浓厚的兴趣。在这里，我们提出了一个 2 × 4 锗量子点阵列，在最近邻自旋之间具有完全且可控的相互作用。为了演示控制级别，我们在此系统中定义了四个单重态-三重量子比特，并展示了每个量子比特的双轴单量子比特控制以及所有相邻量子比特对之间的 SWAP 式双量子比特门，从而产生 99.49（8）–99.84（1）% 的平均单量子比特门保真度和 73（1）–90（1）% 的贝尔状态保真度。结合这些操作，我们实验性地实现了一个电路，旨在在整个阵列中生成和分配纠缠。实现了保真度为 75（2）% 且并发度为 22（4）% 的远程贝尔状态。这些结果突出了单重态-三重态量子比特作为量子计算竞争平台的潜力，并表明在扩展双线性阵列中扩大对量子点自旋的控制是可行的。