Superconducting circuits extensively rely on the Josephson junction as a nonlinear electronic element for manipulating quantum information and mediating photon interactions. Despite continuing efforts in pushing the coherence of Josephson circuits, the best photon lifetimes have been demonstrated in microwave cavities. Nevertheless, architectures based on quantum memories require a qubit element for logical operations at the cost of introducing additional loss channels and limiting process fidelities. Here, we directly operate the oscillator as an isolated two-level system by tailoring its Hilbert space. Implementing a flux-tunable inductive coupling between two resonators, we can selectively Rabi drive the lowest eigenstates by dynamically activating a three-wave interaction through parametric flux modulation. Measuring the Wigner function confirms that we can prepare arbitrary states confined in the single-photon manifold, with measured coherence times limited by the oscillator intrinsic quality factor. This architectural shift in engineering oscillators with stimulated nonlinearity can be exploited for designing long-lived quantum modules and offers flexibility in studying non-equilibrium physics with photons in a field-programmable simulator.

超导电路广泛地依赖于约瑟夫森结作为非线性电子元件来操纵量子信息并介导光子相互作用。尽管不断努力促进约瑟夫森电路的相干性，但微波腔已证明了最佳的光子寿命。然而，基于量子存储器的体系结构需要用于逻辑操作的量子位元素，但其代价是引入了额外的损耗通道并限制了过程的保真度。在这里，我们通过调整其希尔伯特空间，将振荡器直接作为隔离的两级系统进行操作。通过在两个谐振器之间实现通量可调的电感耦合，我们可以通过参数通量调制动态激活三波相互作用来有选择地拉比驱动最低本征态。测量威格纳函数证实了我们可以准备受限于单光子歧管中的任意状态，并且测量的相干时间受振荡器固有品质因数的限制。工程振荡器具有受激非线性的这种结构变化可用于设计长寿命的量子模块，并为在现场可编程模拟器中研究具有光子的非平衡物理提供了灵活性。