Schwinger effect in superconductors

Paolo Solinas and Andrea Amoretti, researchers at the Department of Physics and Francesco Giazotto (NEST and Scuola Normale, Pisa) have discovered that it is possible to create quasi-particle pairs in superconductors by applying a static electric field. The research has been selected for the cover of Physical Review Letters.

In the Fifties Julian Schwinger, one of the greatest physicist of the last century, predicted that a static electric field would create an electron-positron pair from the vacuum. This prediction has not been experimentally verified yet, due to the intensity of the electric field needed (~1018 V/m) that is not accessible in the laboratories.


The new research shows that a similar effect can occur in superconducting materials, but the electric field needed is much smaller (~108 V/m) and can be generated in the laboratories. This result has important theoretical implications and technological applications in different fields from quantum information to metrology.


Paolo Solinas, email:

Andrea Amoretti, email:


P. Solinas, A. Amoretti and F. Giazotto
“Sauter-Schwinger effect in a Bardeen-Cooper-Schrieffer superconductor”
Physical Review Letters 126, 117001 (2021)