Superconducting NbTiN Nanowire Single Photon Detectors with Low Kinetic Inductance
Shigehito Miki, Masanori Takeda, Mikio Fujiwara, Masahide Sasaki, Akira Otomo, Zhen Wang · Applied Physics Express · 2009
We report on the development of superconducting nanowire single photon detectors (SNSPDs) by using NbTiN thin films on single crystal MgO substrates. NbTiN thin films showed fine crystal structure with closer lattice constant to MgO substrates than that of NbN thin films. The transition temperature of 3.5-nm-thick NbTiN films was comparable to, and the resistivity at 20 K was lower than NbN thin films. The kinetic inductance of NbTiN-SNSPDs was ∼25% lower than that of NbN-SNSPD, and system detection efficiency was 1.4% at a 1550 nm wavelength, which is comparable to NbN-SNSPDs.