Low Temperature Transport in Undoped Mesoscopic Structures

摘要

Using high quality undoped GaAs/AlGaAs heterostructures with opticallypatterned insulation between two layers of gates, it is possible to investigatevery low density mesoscopic regions where the number of impurities is wellquantified. Signature appearances of the scattering length scale arise inconfined two dimensional regions, where the zero-bias anomaly (ZBA) is alsoobserved. These results explicitly outline the molecular beam epitaxy growthparameters necessary to obtain ultra low density large two dimensional regionsas well as clean reproducible mesoscopic devices.