Magnetotransport in a random array of antidots

✍ Scribed by F Evers; A.D Mirlin; D.G Polyakov; P Wölfle

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 76 KB
• Volume: 12
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(01)00368-x

✦ Synopsis

We study the quasiclassical magnetoresistance xx (B) of a two-dimensional electron gas scattered by a random ensemble of antidots and, additionally, by a smooth random potential. We demonstrate that the combination of the two types of disorder yields qualitatively new behavior of xx (B). In particular, (i) it induces a novel quasiclassical memory e ect which leads to a strong negative magnetoresistance, with xx (B)˙B -4 , followed with increasing B by saturation at a value determined solely by the background smooth disorder; (ii) for larger B, the interplay of drift in smooth inhomogeneities and scattering by antidots gives rise to a "di usion-controlled percolation", which yields a positive magnetoresistance and xx (B) diverging as a power law in the limit of large B. Experimental relevance to the transport in semiconductor heterostructures is discussed.