Topological transition of Dirac points in a microwave experiment

Matthieu Bellec (1) , Ulrich Kuhl (2) , Gilles Montambaux (3) , Fabrice Mortessagne (2)

1 MOSAIQ
2 LPMC - Laboratoire de physique de la matière condensée
3 LPS - Laboratoire de Physique des Solides

By means of a microwave tight-binding analogue experiment of a graphene-like lattice, we observe a topological transition between a phase with a point-like band gap characteristic of massless Dirac fermions and a gapped phase. By applying a controlled anisotropy on the structure, we investigate the transition directly via density of states measurements. The wave function associated to each eigenvalue is mapped and reveals new states at the Dirac point, localized on the armchair edges. We find that with increasing anisotropy, they are more and more localized at the edges.

Mots clés: Dirac points; topological phase transition; graphene edges states; microwave experiments

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Matthieu Bellec, Ulrich Kuhl, Gilles Montambaux, Fabrice Mortessagne. Topological transition of Dirac points in a microwave experiment. 2012. ⟨hal-00742665v1⟩