Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 22: Superconductivity – Poster I

TT 22.11: Poster

Montag, 9. März 2026, 18:00–20:00, P1

Charge Sensitive Superconducting Transmon Qubits for Infrared Radiation Detection — •Jonathan Huschle¹, Markus Griedel^1,2, Hannes Rotzinger^1,2, and Alexey V. Ustinov^1,2 — ¹Physikalisches Institut (PHI), Karlsruhe Institute for Technology — ²Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute for Technology

In superconductors, the absorption of photons with energies exceeding the energy gap breaks Cooper pairs. This increases the population of quasiparticles, enhances noise, and introduces additional dissipation at microwave frequencies. The coherence of superconducting qubits is particularly sensitive to these effects and can thus serve as probes of quasiparticle dynamics. To enhance the sensitivity, we use a charge susceptible transmon qubit to investigate charge noise. In combination with a controllable infrared radiation source, we study the impact on both the charge noise and the coherence time of the modified transmon qubit. We present the qubit design and report on our measurement results at millikelvin temperatures.

Keywords: infrared radiation; quantum circuits; superconducting qubits; Josephson junctions; quasiparticles