We propose and analyze a passive architecture for realizing on-chip, scalable cascaded quantum devices. In contrast to standard approaches, our scheme does not rely on breaking Lorentz reciprocity. Rather, we engineer the interplay between pairs of superconducting transmon qubits and a microwave transmission line, in such a way that two delocalized orthogonal excitations emit (and absorb) photons propagating in opposite directions. We show how such cascaded quantum devices can be exploited to passively probe and measure complex many-body operators on quantum registers of stationary qubits, thus enabling the heralded transfer of quantum states between distant qubits, as well as the generation and manipulation of stabilizer codes for quantum error correction.

我们提出并分析了一种无源架构，以实现片上可扩展的级联量子器件。与标准方法相比，我们的方案不依赖打破洛伦兹互惠。相反，我们设计了成对的超导跨子量子位和微波传输线之间的相互作用，以使两个离域的正交激发发射（并吸收）在相反方向传播的光子。我们展示了如何利用这种级联的量子设备来被动地探测和测量固定量子位的量子寄存器上的复杂多体算子，从而实现远距离量子位之间的量子态的先驱转移，以及稳定子代码的生成和操纵。量子误差校正。