An alternative view at the zero-bias anomaly of metallic point contacts


  • Kurt Gloos Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FIN-20014 Turku, Finland


Ключові слова:

point contacts, zero-bias anomaly, Kondo effect, spontaneous polarization.


We have studied the zero-bias anomaly of point contacts as function of contact size for a wide range of materials from simple normal metals, superconductors, and magnets to highly correlated heavy-fermion compounds. The size dR of the zero-bias anomaly varied in a universal manner proportional to the square of the contact resistance R between 1 W and 10 kW, that is for contact radii from about 15 nm down to 0.2 nm. Magnetic impurities, two-level systems, or a tunneling barrier are unlikely to be the main source of this anomaly. We suggest instead Kondo-type scattering of the conduction electrons due to a spontaneous electron spin polarization at the point contact.


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Як цитувати

Gloos, K. An Alternative View at the Zero-Bias Anomaly of Metallic Point Contacts. Fiz. Nyzk. Temp. 2009, 35, 1204-1208.



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