Leiden University Student Repository

Abeln, Eduard (2017)

Probing the superconducting properties of NbN and MoSi nanodetectors

Master thesis | Physics (MSc)

We investigate photon counting properties in an NbN superconducting nanodetector, and succesfully do quantum detector tomography. We find qualitative similarities to an earlier tomography result on the same detector, although a larger power range may eliminate anomalies in the numerical fit. Furthermore, we investigate the resistive properties of a MoSi superconducting nanodetector, observing finite resistance below the critical temperature. Measuring current as a function of voltage, we find indications that indeed imply a finite resistance below Tc. Obtaining the critical current for different temperatures and applying a Ginzburg-Landau fit, we find a lower critical temperature than obtained from measurements of resistance as a function of temperature. Finally, we observe that photon counts for MoSi are not possible above T > 3.85 K. We calculate that electronic noise is responsible for this absence of photon counts.

superconductors

detector

photon

Author

Abeln, Eduard

Faculty

Faculty of Science

Specialisation

Physics

Supervisors

Dood, Michiel J.A. de

ECTS Credits

3

Language

en