Robustness of the quantum Hall effect, sample size versus sample topology, and quality control management of III-V molecular beam epitaxy

摘要

We measure the IQHE on macroscopic (1.5cm x 1.5cm) "quick 'n' dirty" preparedIII-V heterostructure samples with van der Pauw and modified Corbino geometriesat 1.3 K. We compare our results with (i) data taken on smaller specimens,among them samples with a standard Hall bar geometry, (ii) results of ournumerical analysis taking inhomogenities of the 2DEG into account. Our mainfinding is a confirmation of the expected robustness of the IQHE which favoursthe development of wide plateaux for small filling factors and very largesample sizes (here with areas 10,000 times larger than in standardarrangements).