Design and Testing of Superconducting Microwave Passive Components for Quantum Information Processing

TL;DR

This paper presents the design, fabrication, and testing of superconducting microwave passive components, specifically a quadrature hybrid and a directional coupler, optimized for integration with quantum information processing systems.

Contribution

It introduces novel superconducting passive microwave components with measured performance metrics suitable for quantum applications, including fabrication and testing results.

Findings

Return loss and isolation > 20 dB

Insertion loss < 0.3 dB in specified bands

Measured center frequency differs by 7% from design

Abstract

We report on the design, fabrication and testing of two superconducting passive microwave components, a quadrature hybrid and a 20 dB directional coupler. These components are designed to be integrated with superconducting qubits or Josephson parametric amplifiers and used in quantum information processing applications. For the coupler, we measure return loss and isolation > 20 dB, and insertion loss < 0.3 dB in a 2 GHz band around 6 GHz. For the hybrid performance, we measure isolation > 20 dB and insertion loss < 0.3 dB in a 10% band around 6.5 GHz. These values are within the design specifications of our application; however, we find a 7% difference between the designed and measured center frequency for the hybrid.