OIST, Yuimaru Kubo
Current quantum information technologies at microwave frequencies require
ultra-low temperature operations, typically at 10 – 100 millikelvin, because of
the tiny energy of microwave photons. One of the key technologies is an
ultra-low noise amplification of microwave signals at millikelvin
environments. This has only been realized by superconducting Josephson
parametric amplifiers (JPA), which are based on superconducting circuits.
However, JPAs have suffered from a smaller saturation power. The
state-of-the-art JPA has a maximum input power of about -100 dBm (0.1 picowatts).
Moreover, JPAs do not properly work under strong magnetic fields due to the