The Aharonov-Bohm effect with nanotubes
(Top left) In the standard Aharonov--Bohm effect the magnetic flux through the solenoid changes the relative phase of the electron waves in paths 1 and 2, leading to the formation of an interference pattern on the screen. When the flux is changed, the interference pattern shifts on the screen. (Top right) In a carbon nanotube, the two paths are clockwise and anticlockwise around the nanotube, and the shift in the interference pattern manifests itself as a change in the electrical resistance along the nanotube as a function of magnetic field (bottom). The magnetic field at the peaks can be related to the quantum of magnetic flux, h/2e, and the cross-section of the nanotube (see Bachtold et al. and Schönenberger et al. in further reading).