Peierls instability and ferrimagnetic ordering of quasi-one-dimensional carbon chains generated in H-passivated graphene

Abstract

Using first-principle density-functional calculations, we investigate the competition between Peierls instability and spin ordering in a zigzag C chain generated in an H-passivated graphene. We find that such a quasi-one-dimensional (1D) C chain of infinite length stabilizes a Peierls instability showing bond alternation with a band-gap opening. As the chain length becomes finite, the Peierls distortion is enhanced at even-numbered chains, while a ferrimagnetic spin ordering with the atomic structure of a topological soliton is stabilized at odd-numbered chains. These results indicate the existence of complex interplay between electron-lattice and electron-electron interactions with respect to the parity of the quasi-1D C chains.