A chiral photonic interface is a quantum system that has different probabilities for emitting photons to the left and right. An on-chip compatible chiral interface is attractive for both fundamental studies of light-matter interactions and applications to quantum information processing. We propose such a chiral interface based on superconducting circuits, which has wide bandwidth, rich tunability, and high tolerance to fabrication variations. The proposed interface consists of a core that uses Cooper-pair boxes (CPBs) to break time-reversal symmetry, and two superconducting transmons that connect the core to a waveguide in the manner reminiscent of a “giant atom.” The transmons form a state decoupled from the core, akin to dark states of atomic physics, rendering the whole interface insensitive to the CPB charge noise. The proposed interface can be extended to realize a broadband fully passive on-chip circulator for microwave photons.

中文翻译：

---

用于波导电路 QED 的电荷噪声不敏感手征光子接口

手性光子界面是一种量子系统，它具有向左和向右发射光子的不同概率。片上兼容的手性界面对于光物质相互作用的基础研究和量子信息处理的应用都很有吸引力。我们提出了一种基于超导电路的手性界面，它具有宽带宽、丰富的可调性和对制造变化的高耐受性。拟议的接口包括一个使用库珀对盒 (CPB) 来打破时间反转对称性的核心，以及两个超导传输器，它们以让人联想到“巨原子”的方式将核心连接到波导。transmons 形成与核心解耦的状态，类似于原子物理学的暗状态，使整个界面对 CPB 电荷噪声不敏感。