Anomalous response of superconducting titanium nitride resonators to terahertz radiation

Abstract

We present an experimental study of KIDs fabricated of atomic layer deposited TiN films, and characterized at radiation frequencies of $350$~GHz. The responsivity to radiation is measured and found to increase with increasing radiation powers, opposite to what is expected from theory and observed for hybrid niobium titanium nitride / aluminium (NbTiN/Al) and all-aluminium (all-Al) KIDs. The noise is found to be independent of the level of the radiation power. The noise equivalent power (NEP) improves with higher radiation powers, also opposite to what is observed and well understood for hybrid NbTiN/Al and all-Al KIDs. We suggest that an inhomogeneous state of these disordered superconductors should be used to explain these observations.

References in corpus (6)

• Disorder-Induced Inhomogeneities of the Superconducting State Close to the Superconductor-Insulator Transition
• Minimal resonator loss for circuit quantum electrodynamics
• Strongly disordered TiN and NbTiN s-wave superconductors probed by microwave electrodynamics
• Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators
• Photon-noise limited sensitivity in titanium nitride kinetic inductance detectors
• Microwave properties of superconducting atomic-layer deposited TiN films

Cited by in corpus (6)

• Equivalence of Optical and Electrical Noise Equivalent Power of Hybrid NbTiN-Al Microwave Kinetic Inductance Detectors
• The effect of magnetic field on the intrinsic detection efficiency of superconducting single-photon detectors
• Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors
• Large Inverse Transient Phase Response of Titanium-nitride-based Microwave Kinetic Inductance Detectors
• Recombination of localized quasiparticles in disordered superconductors
• Strong Reduction of Quasiparticle Fluctuations in a Superconductor due to Decoupling of the Quasiparticle Number and Lifetime