Epitaxial superconducting tunnel diodes for light detection applications
Abstract
We demonstrate epitaxially integrated nanoscale superconductor tunnel diodes, realized using NbN on GaN thin films. Tuning the growth conditions leads to reduced interface defect density and to the emergence of the superconducting coherence peaks in the interface tunneling characteristics. The degree of disorder in the superconductor is correlated with the variance in the order parameter value of different domains. Epitaxial integration of the nanoscale layers allowed precise control on the quality of the superconductor at the interface, and, by extension, the variance in the order parameter value. The numerical calculations taking a normal distribution of superconducting order parameter at the interface with a fixed variance in its order parameter values closely match the measured interface transport characteristics at different temperatures. Strong sub-gap nonlinearity observed in the differential conductivity measurements were subsequently shown to be sensitive to photon incidence, thereby acting as a photodetector. Usage of superconducting interfaces with semiconducting layers such as GaN permit sensitivity tunability and enable large scale device fabrication and integration.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 30, 2020
- Source ID
- 10.1364/ome.395919
Entities
People
- Alex Hayat
- Boaz Taitler
- Debdeep Jena
- Huili Grace Xing
- John Wright
- Krishna Balasubramanian
- Orr Zohar
- Shlomi Bouscher
Organizations
- Israel Science Foundation
- National Science Foundation
- Office of Naval Research