Physica B 169 (1991) North-Holland
Ballistic and adiabatic electron transport
in 1 and 2 dimensions
C.W.J. Beenakker Philips
talk was given
5600 JA Eindhoven.
by the author.
Abstract An overview is given of the work of the PhilipsiDelft collaboration on low-temperature electrical conduction through nanostructures in a two-dimensional electron gas, with an emphasis on the present theoretical understanding of the phenomena observed. The central vehicle for the investigation is the quantum point contact, which is a constriction of variable width comparable to the Fermi wavelength. Two transport regimes are distinguished: Ballistic transport at zero or weak magnetic fields, and adiabatic transport in strong magnetic fields. Major topics are: (i) conductance quantisation; (ii) coherent electron focusing; (iii) electron beam collimation; (iv) electron billiards; (v) edge channels in the integer and fractional quantum Hall effect.