Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 22: Superconductivity – Poster I

TT 22.18: Poster

Monday, March 9, 2026, 18:00–20:00, P1

Dual-tone spectroscopy of atomic tunneling systems in amorphous solids — •Anton Jarecka, Jan Blickberndt, Moritz Maur, Andreas Fleischmann, Andreas Reiser, and Christian Enss — Kirchhoff Institute for Physics, Heidelberg University

The performance of state-of-the-art superconducting quantum devices is limited by noise and decoherence effects, which are known to originate from atomic tunneling systems (TSs) residing in interfaces and dielectric layers. With the goal of further understanding the dielectric properties of such TSs, we investigate their non-equilibrium response by performing radio-frequency dual-tone spectroscopy using a probe and a pump field. For that purpose, we have developed a superconducting microstructured LC-resonator consisting of four identical interdigital capacitors (IDCs) arranged in a Wheatstone bridge setup and two meander inductances, giving rise to two resonance branches. A bulk glass serves as the IDC's dielectric, providing an ensemble of TSs. We use the setup to probe a dielectric volume shared by the two resonances. Therefore, the resonances address the same ensemble of TSs. By tuning the TS-pump field interaction so that the dominant TS Rabi frequencies match the frequency difference of the resonant branches, we can precisely control the dielectric loss of our sample. The measurements are qualitatively described within a framework based on the dressing of tunneling states induced by strong pump fields. Probing these dressed state transitions provides insights into the non-equilibrium dynamics and, consequently, the dielectric response of atomic TSs.

Keywords: atomic tunneling systems; dielectric loss; amorphous dielectrics; microwave resonators