We propose an in-situ tunable chiral quantum system, composed of a quantum emitter coupled to a waveguide based on the Rice-Mele model (where we alternate both the on-site potentials and tunnel couplings between sites in the waveguide array). Specifically, we show that the chirality of photonic bound state, that emerges in the bandgap of the waveguide, depends only on the energy of the qubit; a parameter that is easy to tune in many artificial atoms. In contrast to previous proposals that have either shown imperfect chirality or fixed directionality, our waveguide quantum electrodynamics scheme achieves both perfect chirality and the capability to switch the directionality on demand with just one tunable element in the device. We also show that our model is easy to implement in both state-of-the-art superconducting circuit and quantum dot architectures. The results show technological promise in creating long-range couplers between qubits while maintaining, in principle, zero crosstalk.

我们提出了一个原位可调谐手性量子系统，由耦合到基于 Rice-Mele 模型的波导的量子发射器组成（我们在波导阵列中交替使用现场电位和位点之间的隧道耦合）。具体来说，我们证明了出现在波导带隙中的光子束缚态的手性仅取决于量子比特的能量；在许多人造原子中很容易调整的参数。与之前显示出不完美的手性或固定方向性的提议相比，我们的波导量子电动力学方案实现了完美的手性，并且能够通过设备中的一个可调元件按需切换方向性。我们还表明，我们的模型很容易在最先进的超导电路和量子点架构中实现。结果表明，在原则上保持零串扰的同时，在量子位之间创建远程耦合器方面具有技术前景。