MAGNETIC ELECTRON FOCUSING EFFECT IN GAAS ALGAAS HETEROSTRUCTURE WITHGATE-CONTROLLED BYWAY CHANNEL/

The magnetic electron focusing effect (MEFE) is investigated using a d evice with two extra probes connected by a gate-controlled byway chann el. The focusing peak height is inversely proportional to the byway ch annel resistance. The results show that the focusing peaks are caused by the current through the byway. It is found that, at most, about 9% of the total current hows in the byway when the focusing effect occurs . Moreover, a countercurrent flows in the byway when the focusing effe ct does not occur.