HOT-ELECTRON BALLISTIC TRANSPORT IN 2-DIMENSIONAL STRUCTURES

Quasi ballistic transport in a 2 dimension electron gas was explored and tunneling through an electrostatic barrier induced by metallic gates on the top of the heterostructure was demonstrated. For energies above 36 me V we observed the LO phonon emission, leading to a short mean free path. At energies below the phonon energy we find a mean free path of the order of 2-mu-m, about an order of magnitude longer than expected theoretically for electron interactions. The angular distribution of hot electrons injected from a point source was shown to be collimated and could be steered by controling the electrostatic profile of the injector. In addition we demonstrated operation of electrostatic lens which opens a new branch in semiconductor physics, namely, electron- optics in solids.