Quantum computation and simulation rely on long-lived qubits with controllable interactions. Trapped polar molecules have been proposed as a promising quantum computing platform, offering scalability and single-particle addressability while still leveraging inherent complexity and strong couplings of molecules^1,2,3,4,5. Recent progress in the single quantum state preparation and coherence of the hyperfine-rotational states of individually trapped molecules allows them to serve as promising qubits^{6,7,8,9,10,11}, with intermolecular dipolar interactions creating entanglement^12,13. However, universal two-qubit gates have not been demonstrated with molecules. Here we harness intrinsic molecular resources to implement a two-qubit iSWAP gate using individually trapped X¹Σ⁺ NaCs molecules. By allowing the molecules to interact for 664 μs at a distance of 1.9 μm, we create a maximally entangled Bell state with a fidelity of 94(3)% in trials in which both molecules are present. Using motion–rotation coupling, we measure residual excitation of the lowest few motional states along the axial trapping direction and find them to be the primary source of decoherence. Finally, we identify two non-interacting hyperfine states within the ground rotational level in which we encode a qubit. The interaction is toggled by transferring between interacting and non-interacting states to realize an iSWAP gate. We verify the gate performance by measuring its logical truth table.

量子计算和模拟依赖于具有可控交互的长寿命量子比特。被困的极性分子已被提议作为一种有前途的量子计算平台，提供可扩展性和单粒子寻址性，同时仍然利用分子的固有复杂性和强耦合^1,2,3,4,5。单量子态制备和单个捕获分子的超精细旋转态的相干性的最新进展使它们能够用作有前途的量子比特^{6,7,8,9,10,11}，分子间偶极相互作用产生纠缠^12,13。然而，通用双量子比特门尚未在分子中得到证明。在这里，我们利用内禀分子资源，使用单独捕获的 X¹Σ⁺ NaCs 分子实现双量子比特 iSWAP 门。通过允许分子在 1.9 μm 的距离上相互作用 664 μs，我们在两个分子都存在的试验中创建了一个保真度为 94（3）% 的最大纠缠贝尔态。使用运动-旋转耦合，我们测量了沿轴向陷印方向的最低少数运动状态的残余激发，并发现它们是退相干的主要来源。最后，我们在地面旋转水平中确定了两个不相互作用的超精细态，我们在其中编码了一个量子比特。通过在交互和非交互状态之间传输来切换交互，以实现 iSWAP 门。我们通过测量其逻辑真值表来验证门性能。