Optical tweezers as a micromechanical tool for studying defects in 2D colloidal crystals
Published in In the proceedings of Optical Trapping and Optical Micromanipulation VIII, 2011
Recommended citation: Sungcheol Kim, Lichao Yu, Stephanie Huang, Alexandros Pertsinidis, Xinsheng Ling, "Optical tweezers as a micromechanical tool for studying defects in 2D colloidal crystals." In the proceedings of Optical Trapping and Optical Micromanipulation VIII, 2011. https://doi.org/10.1117/12.897416
1) Vacancy-interstitial pairs can be long-lived but annihilate each other.
2) Tri-vacancies exhibit fluctuating behavior between bound dislocation pairs and local amorphous states.
3) These observations have implications for understanding the nature of 2D melting.
Abstract
This paper reports on some new results from the analyses of the video microscopy data obtained in a prior experiment on two-dimensional (2D) colloidal crystals. It was reported previously that optical tweezers can be used to create mono- and di-vacancies in a 2D colloidal crystal. Here we report the results on the creation of a vacancy interstitial pair, as well as tri-vacancies. It is found the vacancy-interstitial pair can be long-lived, but they do annihilate each other. The behavior of tri-vacancies is most intriguing, as it fluctuates between a configuration of bound pairs of dislocations and that of a locally amorphous state. The relevance of this observation to the issue of the nature of 2D melting is discussed.