Anomalous criticality at the n=0 quantum Hall transition in graphene: The role of disorder preserving chiral symmetry

作者：Kawarabayashi Tohru^*; Morimoto Takahiro; Hatsugai Yasuhiro; Aoki Hideo

来源：Physical Review B, 2010, 82(19): 195426.

DOI：10.1103/PhysRevB.82.195426

We investigate numerically whether the chiral symmetry is the sole factor dominating the criticality of the quantum Hall transitions in disordered graphene. When the disorder respects the chiral symmetry, the plateau-to-plateau transition at the n=0 Landau level is shown to become anomalous (i.e., step functionlike). Surprisingly, however, the anomaly is robust against the inclusion of the uniform next-nearest-neighbor hopping, which degrades the chiral symmetry of the lattice models. We have also shown that the ac (optical) Hall conductivity exhibits a robust plateau structure when the disorder respects the chiral symmetry.

• 出版日期2010-11-12