Flux-induced semiconducting behavior of a quantum network

Abstract

We show that a diamond-shaped periodic network, recently proposed as a model of a spin filter [A. Aharony, O. Entin-Wohlman, Y. Tokura, and S. Katsumoto, Phys. Rev. B 78, 125328 (2008)], is capable of behaving as a $p$-type or an $n$-type semiconductor depending on a suitable choice of the on-site potentials of the atoms occupying the vertices of the lattice and the strength of the magnetic flux threading each plaquette of the network. A detailed study of the density of states of an infinite network is made together with the conductance of finite-sized system to establish the idea.