Topological Excitations in Semiconductor Heterostructures.

Topological defects play an important role in the melting phenomena in two-dimensions. In this work, we report experimental observation of topological defect induced melting in two-dimensional electron systems (2DES) in the presence of strong Coulomb interaction and disorder. The phenomenon is characterised by measurement of conductivity which goes to zero in a Berezinskii- Kosterlitz-Thouless like transition. Further evidence is provided via low-frequency conductivity noise measurements. [ABSTRACT FROM AUTHOR]