Valley currents in graphene by quantum pumping

Date: 5 December 2019

Venue: UAntwerp, Campus Groenenborger, G.U.241 - Groeneborgerlaan 171 - 2020 Antwerpen (route: UAntwerpen, Campus Groenenborger)

Time: 4:00 PM

Organization / co-organization: Condensed Matter Theory

Short description: Condensed Matter Theory lecture presented by Dr. Jing Wang from City University of Hong Kong

Valley currents in graphene by quantum pumping


Graphene, a two dimensional material which is formed by arranging carbon atoms in a hexagonal lattice, has attracted the interest of researchers in the last decade. It was proven to have many unique properties, such as linear dispersion relation at the Dirac point, high electron mobility and so on. All of these properties made graphene a candidate to become the ideal substitute for silicon in the semi-conductor industry. In order to open a band-gap in graphene, we can confine the graphene along a special direction to form graphene ribbon. The confined direction and the width of the ribbon affect the value of the gap. The gap is opened at the Dirac points. As we already known the Dirac points are degeneracy in graphene. Some researchers have focused on the transport property by differing the two degenerated Dirac points which is useful to make valleytronic device. On the other hand quantum pumping is a powerful method to research the transport in mesoscopic system. In this talk I will present work done during my PhD. This covers the transport property of bilayer graphene nano-ribbon and generate a pure valley current in graphene by using the quantum pumping method.

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