McGill.CA / Science / Department of Physics

CPM Seminar

Berry's Phase and Millikelvin Force Microscopy

Geoff Nunes

Dartmouth College

At millikelvin temperatures, electrons in a metal can travel for long distances and still maintain their quantum mechanical phase. Wave-function interference effects then become observable through changes in the macroscopic electrical resistance of the metal. In such previously observed phenomena as Ahranov-Bohm oscillations and universal conductance fluctuations, the phase shifts arise from the interaction between the charge of the electron and the local magnetic field. Recent theoretical work indicates that interference effects should also arise from the Fermionic nature of the electron. Using a home-made atomic force microscope which operates at 30 mK, we have embarked on a search for such Berry's phase effects in micron-scale metal rings.

Thursday, November 11th 1999, 15:30
Ernest Rutherford Physics Building, room 114