Talk given by Dr. Leonid Ponomarenko Recent advances in the fabrication of heterostructures based on 2D atomic crystals have opened up several new directions in graphene research and applications. These structures are made by transferring different 2D materials on top of each other to form 3D stack. There are about dozen known layered materials that can be exfoliated in the form of atomic planes and remain stable in ambient conditions. This provides almost endless possibility for fabricating structures with on demand properties including tunneling transistors and opto-electronic devices. The simplest hetrostructure is made of graphene placed on a thin slab of hexagonal boron nitride (hBN). hBN serves as an ideal, atomically flat substrate that dramatically improves mobility of graphene allowing observation of the fractional quantum Hall effect and ballistic transport over micrometer distances. If in addition, the crystallographic axes of graphene and hBN are aligned, a moiré pattern forms due to small mismatch (~2%) in lattice constant. Such a pattern acts as superlattice potential and has dramatic effect on the band structure and electronic properties of graphene. In more complex structures hBN and other layered materials such as dichalcogenides of transitional metals (MoS2, WS2 etc.) can be used as atomically thin insulators (for example, in graphene double-layer devices) or tunneling barriers. In this talk I will present some recent results from Manchester and Lancaster groups on tunneling transistors and Coulomb drag experiments, as well as the observation of Hofstadter butterfly in graphene based heterostructures.

This event is part of the eventgroup INT Talks

Homepage
https://www.int.kit.edu/events.php

Speaker
Dr. Leonid Ponomarenko

Lancaster University, UK

Organizer
Dr. Igor Gornyi
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Eggenstein-Leopoldshafen
Mail: igor gornyi ∂does-not-exist.kit edu

Targetgroup
Interested / Everyone