We report the room temperature observation of significant ballistic electron transport in shallow etched four-terminal mesoscopic devices fabricated on an InSb/AlInSb quantum well (QW) heterostructure with a crucial partitioned growth-buffer scheme.
Ballistic electron transport is evidenced by a negative bend resistance signature which is quite clearly observed at 295 K and at current densities in excess of 10$^{6}$ A/cm$^{2}$. This demonstrates unequivocally that by using effective growth and processing strategies, room temperature ballistic effects can be exploited in InSb/AlInSb QWs at practical device dimensions.
We describe the influence of hard wall confinement and lateral dimension on the low temperature transport properties of long diffusive channels and ballistic crosses fabricated in an InSb/InxAl1-xSb heterostructure. Partially diffuse boundary scatter
ing is found to play a crucial role in the electron dynamics of ballistic crosses and substantially enhance the negative bend resistance. Experimental observations are supported by simulations using a classical billiard ball model for which good agreement is found when diffuse boundary scattering is included.
