A unique microwave isolator has been created by researchers at the National Astronomical Observatory of Japan (NAOJ), and they have successfully shown for the first time the fundamental idea behind it, which permits compact isolators, which are necessary for upcoming quantum computers. This isolator, which comprises two frequency mixers often seen in radio telescope receivers, opens the way for the creation of large-scale, multi-pixel radio cameras. The article appears in the IEEE Microwave and Wireless Technology Letters publication.
Quantum computers and radio astronomy receivers both require isolators, which are electrical components that regulate the direction of signal propagation.
It is challenging to build an isolator smaller than a few centimeters because most isolators use magnetic materials. The development of massive quantum computers with a million qubits is hampered by this. A 10,000-fold increase in qubit count would require a vast number of components, including isolators, all of which would need to be miniatured. Currently, realized quantum computers only have about 100 qubits. The development of large-format cameras for radio astronomy observations faces the same issue.
Instead of using magnetic materials for an isolator in this new study, the research team used two sets of frequency mixers instead, and they have theoretically and empirically proven the concept. According to Sho Masui, a Project Researcher at the NAOJ Advanced Technology Center (ATC), “This is based on a completely new principle.” “We have developed a unique microwave band circuit device. Additionally, because the novel isolator may produce circuits that are extremely scalable, it is important from an electrical engineering perspective.
The new isolator’s ability to be configured entirely within a flat circuit on a printed circuit board is one of the key scaling advantages. This implies that an integrated circuit isolator, which is 1,000 times less in volume than a traditional isolator, can be downsized to the millimeter scale.
The research team is looking to create isolators that can also magnify signals, which is a greater goal. Superconductor-insulator-superconductor (SIS) mixers, which are frequently employed in radio observation equipment, have the ability to magnify signals. An SIS mixer can be utilized to create a novel device that amplifies signals and serves as an isolator instead of the commercially available semiconductor mixer that is used in this development.
According to NAOJ Director of Engineering Yoshinori Uzawa, “Radio wave observation equipment and quantum computers share some common development elements.” “NAOJ has gained expertise in the creation of observational tools for radio waves, visible light, and infrared light. Recently, we organized a project team to advance technological advancement for the use of quantum computers and launched the Social Implementation Program in the NAOJ ATC. We will keep making advancements in these two areas.