Anatoli V. Melechko

Defect-mediated condensation of a charge density wave

Weitering, H.H., J.M. Carpinelli, A.P. Melechko, J.D. Zhang, M. Bartkowiak, and E.W. Plummer,  

Science, 1999. 285(5436): p. 2107-2110.


We have investigated the (root3×root3 ) to (3×3) phase transition in the alpha phase of Sn/Ge(111) with variable temperature STM at temperatures between 30 and 300 K. Point defects in the Sn film stabilize localized regions of the (3×3) phase, where the size is characterized by a temperature dependent length (exponential attenuation). The inverse of the attenuation length is a linear function of temperature showing that the phase transition occurs at 70 K. At low temperature a density wave mediated defect-defect interaction realigns the defects to be in registry with the (3×3) domains.