Length-dependent charge redistribution in dangling-bond linear chains which had been fabricated on a H-terminated (100)-(2 x 1) surface was analyzed by means of scanning tunnelling microscopy and first-principles calculations. The second-layer Si atoms were displaced alternately so as to form pairs with charge redistribution, which was explained by the Jahn-Teller distortion in an artificial pseudo-molecule. In a short even-numbered dangling-bond structure, an unpaired second-layer Si atom existed and behaved as a soliton, accompanied by a flip-flop motion of the structure. It was concluded that the odd-even disparity, the edge effect and the finite lengths of the dangling-bond structures were essential to any understanding of relaxation in the structures.

Jahn-Teller Distortion in Dangling-Bond Linear Chains Fabricated on a H-Terminated Si(100)-(2 x 1) Surface T.Hitosugi, S.Heike, T.Onogi, T.Hashizume, S.Watanabe, Z.Q.Li, K.Ohno, Y.Kawazoe, T.Hasegawa, K.Kitazawa: Physical Review Letters, 1999, 82[20], 4034-7