A Unidirectional On-Chip Photonic Interface for Superconducting Circuits

TL;DR

This paper introduces a passive, scalable on-chip photonic interface for superconducting circuits that enables directional photon emission and absorption without breaking Lorentz reciprocity, facilitating quantum state transfer and error correction.

Contribution

It presents a novel passive architecture for on-chip quantum devices that uses engineered qubit interactions to achieve directional photon flow without nonreciprocal components.

Findings

Enables heralded quantum state transfer between distant qubits

Allows passive probing of complex many-body operators

Supports generation and manipulation of quantum error correction codes

Abstract

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.