Regensburg 2022 – wissenschaftliches Programm
QI 4.24: Poster
Montag, 5. September 2022, 18:00–20:00, P2
Thermo-optical properties of superconducting thin films for waveguide-integrated single-photon detectors. — •Anthony Chukwunonso Ogbuehi1,2, Pierre Piel1,2, Martin Wolff1,2, Matthias Häussler1,2, Carsten Schuck1,2, and Ursula Wurstbauer1,2 — 1Institute of Physics, Münster University, Germany — 2Center for Soft Nanoscience SoN, Münster University, Germany
Integrated quantum photonics relies on the generation, manipulation, and measurement of single quantum states of light. The latter can be achieved with superconducting nanowire single-photon detectors (SNSPD) embedded into photonic integrated circuits . While SNSPDs show attractive detection efficiency and high timing accuracy , it remains largely unknown how detector performance characteristics are connected to superconducting material properties. Here we study the temperature-dependent dielectric function of niobium-titanium nitride (NbTiN) thin films above and below the critical temperature by means of spectroscopic ellipsometry by varying a number of parameters. Material optimization guided by spectroscopic ellipsometry provides a novel approach for both getting new insight into key parameters of the detection process and improving single-photon detector benchmarks, benefitting a wide range of integrated quantum technology applications.
 S. Ferrari et al., Nanophotonics 7, 1725 (2018)  M. A. Wolff et al., Appl. Phys. Lett. 118, 154004 (2021).