Design and Performance of Hafnium Optical and Near-IR Kinetic Inductance Detectors

Abstract

We report on the design and performance of Microwave Kinetic Inductance Detectors (MKIDs) sensitive to single photons in the optical to near-infrared range using hafnium as the sensor material. Our test device had a superconducting transition temperature of 395 mK and a room temperature normal state resistivity of 97 $\mu \Omega$ cm with an RRR = 1.6. Resonators on the device displayed internal quality factors of around 200,000. Similar to the analysis of MKIDs made from other highly resistive superconductors, we find that modeling the temperature response of the detector requires an extra broadening parameter in the superconducting density of states. Finally, we show that this material and design is compatible with a full-array fabrication process which resulted in pixels with decay times of about 40 $\mu$s and resolving powers of ~9 at 800 nm.

References in corpus (7)

• Number fluctuations of sparse quasiparticles in a superconductor
• Strongly disordered TiN and NbTiN s-wave superconductors probed by microwave electrodynamics
• Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators
• Wide-band Parametric Amplifier Readout and Resolution of Optical Microwave Kinetic Inductance Detectors
• Large-format platinum silicide microwave kinetic inductance detectors for optical to near-IR astronomy
• High Quality Factor Platinum Silicide Microwave Kinetic Inductance Detectors
• Electromagnetic properties of impure superconductors with pair-breaking processes

Cited by in corpus (5)

• Resolving Power of Visible to Near-Infrared Hybrid $\beta$-Ta/NbTiN Kinetic Inductance Detectors
• Estimating the Energy Threshold of Phonon-mediated Superconducting Qubit Detectors Operated in an Energy-Relaxation Sensing Scheme
• Study of quasi-particle dynamics using the optical pulse response of asuperconducting resonator
• Investigation of reflection-based measurements of microwave kinetic inductance detectors in the optical bands
• Membrane-less phonon trapping and resolution enhancement in optical microwave kinetic inductance detectors