Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Coulomb Blockade of Andreev Reflection in the NSN Single Electron Transistor



Travis M. Eiles, Michel H. Devoret, John M. Martinis


We have measured at low temperatures the current through a submicrometer superconducting island connected to nornal metal leads by ultrasmall tunnel junctions. At low bias voltages, the current changes from being e-periodic in the applied gate change to 2e-periodic. We interpret this 2e-periodic current as a manifestation of a sequence of Andreev reflection events which transports two electrons at a time across the island. This behavior is clear evidence that there is a difference in total energy between ground states of differing electron number parity.
Physica B-Condensed Matter
Part 1


Andreev reflection, Coulomb blockade, general superconductivity, ultra-small tunnel junctions


Eiles, T. , Devoret, M. and Martinis, J. (1994), Coulomb Blockade of Andreev Reflection in the NSN Single Electron Transistor, Physica B-Condensed Matter (Accessed April 13, 2024)
Created January 31, 1994, Updated October 12, 2021