TY - DATA T1 - Data underlying the publication: Vibrational modes as the origin of dielectric loss at 0.27–100 THz in a-SiC:H PY - 2024/10/25 AU - Bruno Buijtendorp UR - DO - 10.4121/523d71a0-34ce-4969-a899-00668b9f3265.v1 KW - mm-submm KW - loss KW - dielectric KW - silicon carbide KW - amorphous KW - hydrogenated KW - vibrational modes KW - superconducting N2 -

Low-loss deposited dielectrics are beneficial for the advancement of superconducting integrated circuits for astronomy. In the microwave band (∼1–10 GHz) the cryogenic and low-power dielectric loss at cryogenic temperatures and low electric field strengths is dominated by two-level systems. However, the origin of the loss in the millimeter-submillimeter band (∼0.1–1 THz) is not understood. We measured the loss of hydrogenated amorphous SiC (a-SiC:H) films in the 0.27–100 THz range using superconducting microstrip resonators and Fourier-transform spectroscopy. The agreement between the loss data and a Maxwell-Helmholtz-Drude dispersion model suggests that vibrational modes above 10 THz dominate the loss in the a-SiC:H above 200 GHz.

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