Ultra-sensitive Detector and Broadband Quantum-limited Amplifier Based on Nitride Superconductors
Jiansong Gao
Quantum Device Group, NIST Boulder
Superconducting nitrides, such as TiN and NbTiN,
show many ideal properties for microwave kinetic inductance detectors (MKIDs)
such as extremely low loss, large kinetic inductance, and tunable Tc. In
addition, its unique nonlinearity with very low dissipation can be used to
build a novel broadband quantum-limited microwave parametric amplifier called kinetic
inductance amplifier (KIT), which has important applications in readout of
superconducting detectors and quantum bits (qubits). In this talk, I will
present our recent progress in the development of TiN/NbTiN-based detectors and
amplifiers. These detectors are approaching photon noise limit and the KIT
amplifiers have achieved over 4 GHz of bandwidth with gain exceeding 20 dB.