Phys. Rev. Lett. 79, 3486–3489 (1997)Observation of Andreev Reflection Enhanced Shot NoiseReceived 18 June 1997; published in the issue dated 3 November 1997 We have experimentally investigated the quasiparticle shot noise in NbN/MgO/NbN superconductor-insulator-superconductor tunnel junctions. The observed shot noise is significantly larger than theoretically expected. We attribute this to the occurrence of multiple Andreev reflection processes in pinholes present in the MgO barrier. This mechanism causes the current to flow in large charge quanta (Andreev clusters), with a voltage dependent average value of m≈1+2Δ/eV times the electron charge. Because of this charge enhancement effect, the shot noise is increased by the factor m. © 1997 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.79.3486
DOI:
10.1103/PhysRevLett.79.3486
PACS:
74.50.+r, 72.70.+m, 74.80.Fp
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.