The magnetoconductance of nominally identical, 2-, um-long, Au lines has been measured.
A 0.7-, um-diam loop was attached to the end of one of the lines outside the probes in such a
way that classically no current would flow through it. As expected, the line by itself showed
only aperiodic conductance fluctuations. In contrast, the line with the attached loop also
exhibited h Ie periodic oscillations. The periodic oscillations are due to the quantum
interference of electrons diffusing around the loop. These results clearly demonstrate that …