We have fabricated two types of lumped-element Josephson parameter amplifiers（JPAs） by using a multilayer microfabrication process involving wet etching of Al films. The first type is a narrow band JPA which shows t...We have fabricated two types of lumped-element Josephson parameter amplifiers（JPAs） by using a multilayer microfabrication process involving wet etching of Al films. The first type is a narrow band JPA which shows typical gain above14 dB in a bandwidth around 35 MHz. The second type is a wideband JPA which is coupled to an input 50Ω transmission line via an impedance transformer that changes the impedance from about 15 Ω on the non-linear resonator side to 50 Ωon the input transmission line side. The wideband JPA could operate in a 200 MHz range with a gain higher than 14 d B.The amplifiers were used for superconducting qubit readout. The results showed that the signal to noise ratio and hence the readout fidelity were improved significantly.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91321208,11374344,11404386,11574380,and 11674376)the Ministry of Science and Technology of China(Grant Nos.2014CB921401 and 2016YFA0300601)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07010300)
文摘We have fabricated two types of lumped-element Josephson parameter amplifiers（JPAs） by using a multilayer microfabrication process involving wet etching of Al films. The first type is a narrow band JPA which shows typical gain above14 dB in a bandwidth around 35 MHz. The second type is a wideband JPA which is coupled to an input 50Ω transmission line via an impedance transformer that changes the impedance from about 15 Ω on the non-linear resonator side to 50 Ωon the input transmission line side. The wideband JPA could operate in a 200 MHz range with a gain higher than 14 d B.The amplifiers were used for superconducting qubit readout. The results showed that the signal to noise ratio and hence the readout fidelity were improved significantly.
