Shot-noise and conductance measurements of transparent superconductor/two-dimensional electron gas junctions
Abstract
We have measured the conductance and shot noise of superconductor-normal metal (S-N) junctions between a niobium (Nb) film and a two-dimensional electron gas (2DEG), formed in an InAs-based semiconductor heterostructure. Adjacent to the junction, the 2DEG is shaped into a sub-micrometer beam splitter. The current shot noise measured through one arm of the beam splitter is found to be enhanced due to Andreev reflection. Both noise and conductance measurements indicate that the Nb-2DEG interface is of high quality with a transparency approaching ≈60-70% . The present device can be seen as a quasi-ballistic S-N beam-splitter junction.
- Publication:
-
Physical Review B
- Pub Date:
- July 2005
- DOI:
- arXiv:
- arXiv:cond-mat/0410621
- Bibcode:
- 2005PhRvB..72b4501C
- Keywords:
-
- 74.78.Na;
- 73.23.-b;
- 74.45.+c;
- 72.70.+m;
- Mesoscopic and nanoscale systems;
- Electronic transport in mesoscopic systems;
- Proximity effects;
- Andreev effect;
- SN and SNS junctions;
- Noise processes and phenomena;
- Condensed Matter - Mesoscopic Systems and Quantum Hall Effect
- E-Print:
- full paper including figures can be retrieved from: http://www.unibas.ch/phys-meso/Research/Papers/2004/Shot-Noise-Yjunction.pdf