Symmetry breaking during nanocrystal growth.

Symmetry breaking is a ubiquitous phenomenon that occurs spontaneously when a system is subjected to changes in size and/or variations in terms of thermodynamic parameters. As a stochastic process, even small fluctuations acting on a system can arbitrarily push it down one of the branches of a bifurcation. In this feature article, we use nanocrystal growth to illustrate the concept of symmetry breaking. Our aim is to convey its importance from a mechanistic perspective, by which one can rationally alter the experimental conditions to manipulate the growth pattern (symmetric vs. asymmetric) and thus generate colloidal nanocrystals with controlled shapes, structures, and properties for various applications.