Aharonov-Bohm effect in semiconductor microstructures

In this Letter we present a simple theory for the Aharonov-Bohm effect in semiconductor microstructures, assuming ballistic transport. It is shown that in well-designed symmetric structures it may be possible to attain large (approaching 100% in principle) conductance modulation in a magnetic field even if the transverse dimension of the structure is large, the aspect ratio is poor, and $k_B$T exceeds the correlation energy. The theoretical formulation can also be used to describe the electrostatic effect which has not yet been observed.