Magic-angle twisted bilayer graphene (MATBG) hosts a number of correlated states of matter that can be tuned by electrostatic doping^1,2,3,4. Transport^5,6 and scanning-probe^7,8,9 experiments have shown evidence for band, correlated and Chern insulators along with superconductivity. This variety of in situ tunable states has allowed for the realization of tunable Josephson junctions^10,11,12. However, although phase-coherent phenomena have been measured^10,11,12, no control of the phase difference of the superconducting condensates has been demonstrated so far. Here we build on previous gate-defined junction realizations and form a superconducting quantum interference device¹³ (SQUID) in MATBG, where the superconducting phase difference is controlled through the magnetic field. We observe magneto-oscillations of the critical current, demonstrating long-range coherence of superconducting charge carriers with an effective charge of 2e. We tune to both asymmetric and symmetric SQUID configurations by electrostatically controlling the critical currents through the junctions. This tunability allows us to study the inductances in the device, finding values of up to 2 μH. Furthermore, we directly probe the current–phase relation of one of the junctions of the device. Our results show that complex devices in MATBG can be realized and used to reveal the properties of the material. We envision our findings, together with the established history of applications SQUIDs have^14,15,16, will foster the development of a wide range of devices such as phase-slip junctions¹⁷ or high kinetic inductance detectors¹⁸.

魔角扭曲双层石墨烯 (MATBG) 拥有许多相关的物质状态，可以通过静电掺杂^1,2,3,4进行调整。传输^5,6和扫描探针^7,8,9实验显示了能带、相关和陈绝缘体以及超导性的证据。这种原位可调状态的多样性允许实现可调约瑟夫森结^10,11,12。然而，虽然相位相干现象已经被测量^10,11,12，但到目前为止还没有证明对超导凝聚物的相位差的控制。在这里，我们建立在以前的门定义结实现的基础上，形成了一个超导量子干涉装置¹³(SQUID) 在 MATBG 中，超导相位差通过磁场控制。我们观察到临界电流的磁振荡，证明有效电荷为 2 e的超导载流子的长程相干性。我们通过静电控制通过结点的临界电流来调整不对称和对称 SQUID 配置。这种可调性使我们能够研究器件中的电感，找到高达 2 μH 的值。此外，我们直接探测器件其中一个结点的电流-相位关系。我们的结果表明，MATBG 中的复杂设备可以实现并用于揭示材料的特性。我们设想了我们的发现，以及 SQUID 已经建立的应用历史^14,15,16，将促进各种设备的发展，例如相滑结¹⁷或高动能电感检测器¹⁸。