Juan Palacios1 Julio Gomez-Herrero1 Sahar Pakdel1 Felix Zamora1 Pablo Ares1

1, Univ Autonoma-Madrid, Madrid, , Spain

Antimony has been recently demonstrated to be amenable to standard exfoliation procedures [1], opening the possibility of studying the electronic properties of isolated few-layered flakes (generically referred to as antimonene). Antimony is a topological semimetal, meaning that its electronic structure presents topologically protected surface states, but it is still trivially metallic in bulk. Antimonene, on the other hand, may present a much reduced electronic bulk contribution for a small number of layers. A novel technique to make electrical contacts on the surface of individual thin flakes (5-10 monolayers) has allowed us to measure the (surface) conductivity of these in ambient conditions. Our measurements reveal a sheet resistance comparable to that of graphene, which we mainly attribute to the topologically protected surface electrons. We have carried out theoretical work to support this claim, addressing, in particular, the relative importance of bulk and surface conductivity and their scaling properties. Our calculations are based on density functional theory for the electronic structure and Kubo formalism for the conductivity, the latter considering random disorder and the presence of water [2].

[1] P. Ares et al., Advanced Materials 28, 6515 (2016)
[2] S. Pakdel et al, in preparation.