Physicists have built the world’s thinnest wires, one atom wide, by evaporating a puff of gold atoms onto a silicon substrate which has first been cleared of impurities by baking it at 1200 degrees Kelvin.

The crystalline surface was cut to form staircase corrugations. Left to themselves, the atoms then self-assemble into wires (aligned along the corrugations) of up to 150 atoms each.