Microwave Losses in YBCO Coplanar Waveguide Resonators at Low Power and Millikelvin Range

Author

Arzeo, Marco ; Lombardi, Floriana ; Bauch, Thilo

Author_Institution

Dept. of Microtechnol. & Nanosci., MC2, Chalmers Univ. of Technol., Goteborg, Sweden

Volume

25

Issue

3

fYear

2015

fDate

Jun-15

Firstpage

1

Lastpage

4

Abstract

We have investigated the temperature dependence of microwave losses in the low-power limit and millikelvin temperature range of a thin-film YBa₂Cu₃O_7-x (YBCO) λ/2 coplanar waveguide resonator patterned on a (La_0.3Sr_0.7) (Al_0.65Ta_0.35)O₃ (LSAT) substrate covered by a CeO₂ seed layer. The unloaded quality factor is mainly governed by the surface resistance of the YBCO film and the dielectric losses caused by resonant absorption due to a bath of two-level fluctuators in the dielectrics. The value of the unloaded quality factor at 20 mK and low power, i.e., Q₀ ≃2000, allows for the realization of YBCO microwave quantum circuits implementing biepitaxial grain-boundary Josephson junctions.

Keywords

Q-factor; cerium compounds; coplanar waveguides; dielectric losses; lanthanum compounds; microwave circuits; microwave resonators; superconducting junction devices; surface resistance; thermal analysis; thin films; yttrium compounds; (La_0.3Sr_0.7)(Al_0.65Ta_0.35)O₃; CeO₂; YBa₂Cu₃O_7-x; biepitaxial grain-boundary Josephson junctions; dielectric losses; microwave losses; microwave quantum circuits; milliKelvin temperature range; quality factor; resonant absorption; seed layer; surface resistance; temperature 20 mK; temperature dependence; thin-film coplanar waveguide resonator; two-level fluctuators; Dielectric losses; Josephson junctions; Microwave theory and techniques; Superconducting microwave devices; Yttrium barium copper oxide; Dielectric losses; high critical temperature supreconductors; superconducting microwave devices; superconducting thin films; surface resistance; yttrium barium copper oxide (YBCO);

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2014.2364777

Filename

6936352