  We demonstrate the existence of atomically-sized topological solitons in a
quasi one-dimensional charge density wave system: indium atomic wires on
Si(111). Performing joint scanning tunneling microscopy and density-functional
calculations, we show that the Si(111)-(8x2)In surface features two
conceptually different types of abrupt phase flip structures. One is caused by
In adatoms and is, hence, non-solitonic in nature. The other one is an abrupt
left-chiral soliton.
