Presentation Information
[22a-P01-18]Evaluation of Surface Resistance of NbTiN Thin Films in Millimeter-wave Band
〇(M1)Jumpei Ohkami1, Sho Masui2, Takafumi Kojima2, Hirotaka Terai3, Masanori Takeda1 (1.Shizuoka Univ., 2.NAOJ, 3.NICT)
Keywords:
superconductivity,surface resistance
We aim to realize a traveling-wave superconducting parametric amplifier (KITWPA) operating in the millimeter-wave band. Polycrystalline NbTiN thin films with high resistivity and large kinetic inductance are often used for microwave KITWPAs. However, in the millimeter-wave band, the surface resistance of the superconducting thin film is significantly higher than in the microwave band, and there is concern about a significant reduction in gain due to transmission loss. On the other hand, it is known that NbTiN films can be epitaxially grown on MgO substrates, and their resistivity is smaller than that of polycrystalline NbTiN films. In this study, we fabricated half-wavelength resonators of NbTiN thin films on MgO and sapphire substrates and evaluated their surface resistivity in order to select materials and analyze the gain of millimeter-wave band KITWPA.