Researchers at the University of Queensland (UQ) have developed a new design for a passive, integrated, on-chip, superconducting microwave circulator with high bandwidth (~500 MHz).
Microwave circulators are ubiquitous elements in microwave electronics and are essential to both fundamental science as well as commercial technology such as radar and mobile phone communications. Commercially available circulators are wave-interference devices based on the Faraday effect, which requires relatively strong permanent magnets to break time-reversal symmetry. Both their size and the necessary strong magnetic fields make them unsuited to large-scale integration with superconducting circuits.
The design by UQ researchers is based on superconducting tunnel junctions, either Josephson (JJ) or quantum phase slip (QPS) junctions in a ring geometry. Two further improvements have been demonstrated in a second-generation design which increases linearity of circuits, as well as development of a design approach that increases bandwidth and reduces sensitivity to perturbations in external bias parameters.
Key benefits:
- Replaces large (cm-scale) discrete component with small on-chip integrated component
- High bandwidth and high power design
- Key enabler for superconducting quantum devices and computing
- Small footprint and device volume scales to arrays of 10,000s with existing tools and processes.