Transport in disordered two-dimensional materials
Chi-Te Liang1*
1Department of Physics, National Taiwan University, Taipei, Taiwan
* presenting author:Chi-Te Liang,
Two-dimensional (2D) materials [1] such as graphene, MoS2, WSe2, etc. have been attracting much interest because of their fundamental importance as well as their potential device applications. In this talk I will concentrate on disordered 2D materials in which interesting physical phenomena can be observed. First, I shall describe charge transport in a monolayer MoS2 flake over a wide range of carrier density, temperature and electric bias. We find that the transport is best described by a percolating picture in which the disorder breaks translational invariance, breaking the MoS2 system up into a series of electron puddles, rather than previous pictures in which the disorder is treated as uniform and homogeneous. Our work provides useful insight to a unified picture of charge transport in monolayer MoS2 nanoflakes. In the second part of my talk, I shall describe strongly insulating behaviour observed in monolayer epitaxial graphene grown on SiC and its relevance to the semi-circle law, temperature-driven flow, and the direct insulator-quantum Hall transition in two dimensions [2].

This work was done in collaboration with C. Chuang. R. E. Elmquist, A. R. Hamilton, L.-I. Huang, O. Klochan, C.-H. Liu, S.-T. Lo, W. H. Wang, and Y. Yang. I would like to acknowledge financial support from the Ministry of Science and Technology (MOST), Taiwan (grant numbers: MOST 102-2119-M-002-016-MY3 and MOST 103-2918-I-002-028) and National Taiwan University (grant numbers: 102R7863, 103R7552-2 and 104R7552-2)

[1] V. I. Fal'ko, 2D Mater. 1, 010201 (2014).
[2] C.-T. Liang and S.-T. Lo, Chin. J. Phys. 52, 1175 (2014).

Keywords: Graphene, MoS2<\sub>, Disordered, Phase transition, Hopping