Quantum and non-linear forces yield peculiar thermal expansion in silicon

Most materials expand when heated. At temperatures below room temperature, silicon shows the opposite behavior, shrinking as it is heated. Even at room temperature the normal thermal expansion of silicon is rather small. A team led by Professor Brent Fultz wanted to know why, and found that the unusual property is the result of quantum effects coupled by the nonlinear forces between atoms in silicon. [Read the paper]