LA13215

Binary Bonds

By pulling on an individual atom with an atomically sharp probe, the smallest toggle switch achievable in silicon has been realised. The switch is flipped by reorienting a single chemical bond through mechanical force alone. Although atom switches have previously been reported by a number of research groups, in each case the switching mechanism has required, or involved, a flow of electrons. In this paper we show that a silicon atom can be toggled back and forth between an ‘up’ and a ‘down’ position by directly modifying the bond it makes with its nearest neighbour. This is achieved through manipulation of the force between two atoms – an electric current or a bias voltage is not necessary – and results in binary control of bond angle. The ability to switch the orientation of a single chemical bond in this way is an important new addition to the nanotechnologist’s toolbox.