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Photon-noise limited sensitivity in titanium nitride kinetic inductance detectors



Johannes Hubmayr, James A. Beall, Daniel T. Becker, Hsiao-Mei Cho, Gene C. Hilton, Dale Li, David P. Pappas, Jeffrey L. Van Lanen, Mark Devlin, Kent D. Irwin, Chris Groppi, Phillip Mauskopf


We demonstrate photon-noise limited performance at sub-millimeter wavelengths in microwave kinetic inductance detectors (MKIDs) made of a new superconducting material, a TiN/Ti/TiN trilayer film. Optical coupling is achieved by use of feedhorns, a standard approach at sub-millimeter wavelengths that is an emerging MKID coupling scheme. The lumped-element detector design enables dual-polarization sensitivity. The devices are fabricated on a silicon-on-insulator (SOI) wafer. Micro-machining of the SOI wafer backside creates a quarter-wavelength backshort optimized for efficient coupling at 250 μm. When viewing a variable temperature thermal source, devices show noise consistent with that due to photon fluctuations at photon loads > 1 pW, suitable for broadband photometric applications.
Applied Physics Letters


Hubmayr, J. , Beall, J. , Becker, D. , Cho, H. , Hilton, G. , Li, D. , Pappas, D. , Van, J. , Devlin, M. , Irwin, K. , Groppi, C. and Mauskopf, P. (2015), Photon-noise limited sensitivity in titanium nitride kinetic inductance detectors, Applied Physics Letters, [online], (Accessed April 21, 2024)
Created February 20, 2015, Updated November 10, 2018