SKM 2023 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 57: Poster: Superconductivity I
TT 57.22: Poster
Thursday, March 30, 2023, 15:00–18:00, P2/OG2
Realization of He-FIB induced Josephson junction THz detectors in YBCO thin films — •Kenny Fohmann, Christoph Schmid, Eric Dorsch, Edward Goldobin, Dieter Koelle, and Reinhold Kleiner — Physikalisches Institut, Center for Quantum Science (CQ) and LISA+, Universität Tübingen, Germany
We designed and fabricated ultrawideband thin-film antennas from the high-temperature superconductor YBa2Cu3O7−δ (YBCO) partially covered with Au. By using a focused He ion beam (He-FIB) we “draw” a Josephson Junction (JJ) [1] into the microbridge footpoint of the spiral antenna. Under microwave irradiation the JJ exhibits Shapiro steps in the I−V characteristic.
We report on design optimization. This includes improved matching of the impedances of the antenna and the JJ in an ultrawide frequency band by using a logarithmic periodic antenna. Moreover, we performed simulations using CST Studio-Suite to improve the coupling of a plane-wave signal to the antenna.
To characterize the antennas, we compare the excitation of the JJ embedded in a simple linear YBCO bridge (∼ 1 mm) with the one embedded in the footpoint of the antenna, for frequencies up to 40 GHz.
The ultimate goal of such an antenna with a YBCO JJ is to detect the radiation from a BSCCO-mesa (placed on another chip nearby) in the frequency range 0.5 THz. The latest measurements will be presented.
[1] B. Müller et al., Phys. Rev. Appl. 11, 044082 (2019)