Magnetic-free traveling-wave nonreciprocal superconducting microwave components

TL;DR

This paper introduces a superconducting, magnetic-free, broadband nonreciprocal microwave isolator and circulator using temporal modulation and integrated transmission lines, suitable for cryogenic quantum computing applications.

Contribution

It presents a novel waveguide-based design for broadband nonreciprocal microwave components without magnetic materials, using superconducting circuits and temporal modulation techniques.

Findings

Achieves 580 MHz bandwidth with 20 dB isolation

Uses integrated superconducting transmission lines

Provides on-chip solutions for cryogenic microwave systems

Abstract

We propose a design to realize integrated broadband nonreciprocal microwave isolators and circulators using superconducting circuit elements without any magnetic materials. To obtain a broadband response, we develop a waveguide-based design by temporal modulations. The corresponding compact traveling-wave structure is implemented with integrated superconducting composite right-/left-handed transmission lines. The calculations show that the bandwidth of 580 MHz can be realized over a nonreciprocal isolation of 20 dB in reflections. Such on-chip isolators and circulators are useful for cryogenic integrated microwave connections and measurements, such as protecting qubits from the amplified reflected signal in multiplexed readout.