- 24.07.2017 -
NEST Seminar: prof. Jeil Jung
Prof. Jeil Jung (Department of Physics, University of Seoul, Seoul 02504, Korea)
24/07/2017, 11:00 @ NEST Seminar room
"Moire superlattices in Dirac crystals"
Abstract: When 2D materials are layered to form a vertical heterostructure they often form incommensurable noncrystals that exhibit long-period moire patterns
when examined with scanning probes. In this presentation I will give an overview of methodology that uses information obtained from ab initio calculations performed on locally commensurate crystalline structures to derive effective Hamiltonians that are able to efficiently describe the influence of the moire pattern superlattices on electronic properties. We applied our approach to obtain the Hamiltonian of semimetal and gapped layered Dirac crystal combinations among which we focus on the properties of graphene/boron nitride (G/BN) as a representative system consisting of moire superlattice pattern of pseudospin fields with different topology. We show that moire strains can play an important role in reconfiguring the mechanical and electronic properties of G/BN in the limit of long moire pattern periods and leads to the emergence of a global band gap.
References:
[1] J. Jung, A. Raoux, Z.H. Qiao and A. H. MacDonald, ‘Ab-Initio Theory of Moiré Superlattice Bands in Layered Two-Dimensional Materials’, Physical Review B 89, 205414 (2014).
[2] J. Jung, A. DaSilva, A. H. MacDonald, and S. Adam, ‘Origin of band gaps in graphene on hexagonal boron nitride’, Nature Communications 6:6308 (2015).
[3] N. Leconte, A. Ferreira, and J. Jung, ‘Efficient multiscale lattice simulations of strained and disordered graphene’, Chapter 2 of 'Semiconductors and semimetals, 2D materials’, Elsevier 2016.
[4] J. Jung, E. Laksono, A. DaSilva, M. Mucha-Kruczynski, A. H. MacDonald, S. Adam, to appear.
Host: Stefan Heun
Info stefan.heun@nano.cnr.it
Link http://www.nano.cnr.it/?mod=men&id=116