A coaxial line architecture for integrating and scaling 3D cQED systems

TL;DR

This paper presents a coaxial transmission line architecture for 3D cQED systems that maintains high coherence, reduces loss, and simplifies integration, advancing scalable quantum computing hardware.

Contribution

Introduction of a novel coaxial line architecture for 3D cQED that achieves high coherence and seamless integration of multiple quantum components.

Findings

Achieved coherence comparable to traditional 3D cQED systems.

Demonstrated well-controlled couplings without cross-talk.

Integrated multiple quantum components on a single chip.

Abstract

Numerous loss mechanisms can limit coherence and scalability of planar and 3D-based circuit quantum electrodynamics (cQED) devices, particularly due to their packaging. The low loss and natural isolation of 3D enclosures make them good candidates for coherent scaling. We introduce a coaxial transmission line device architecture with coherence similar to traditional 3D cQED systems. Measurements demonstrate well-controlled external and on-chip couplings, a spectrum absent of cross-talk or spurious modes, and excellent resonator and qubit lifetimes. We integrate a resonator-qubit system in this architecture with a seamless 3D cavity, and separately pattern a qubit, readout resonator, Purcell filter and high-Q stripline resonator on a single chip. Device coherence and its ease of integration make this a promising tool for complex experiments.