Valley Filters in Graphene
Feng-Wu Chen2*, Jia-Huei Jiang2, Yan-Ru Lin1, Ning-Yuan Lue1, Mei-Yin Chou3,4,5, Yu-Shu G. Wu1,2
1Department of Electrical Engineering, National Tsing-Hua University, Hsin-Chu 30013, Taiwan
2Department of Physics, National Tsing-Hua University, Hsin-Chu 30013, Taiwan
3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
4Department of Physics, National Taiwan University, Taipei 10617, Taiwan
5School of Physics, Georgia Institute of Technology, Atlanta, GA 30327, USA
* Presenter:Feng-Wu Chen,
Recently, valleytronics1 has emerged as a possible next-generation electronics, in which the valley pseudospin, an extra degree of freedom (DOF) for electrons exists due to the honeycomb lattice structure in graphene and plays as the fundamental unit for information storage and processing. Furthermore, based on the mechanism of valley-orbit interaction the device structures for qubits2 and field effect transistors3 have all been proposed, serving as the building blocks for the implementation of all – electrical gate controllable valleytronics. In this presentation, we will demonstrate theoretically the feasibility of forming valley filters with this crucial feature, i.e., the ability to switch the valley DOF in an all electrical manner in graphene nanowire. Beyond that, the inverse valley-Hall effect in a graphene nanowire structure will also be demonstrated.

[1] Rycerz et al., Nat. Phys. 3 (2007),172; Xiao et al., Phys. Rev. Lett. 99, (2007), 236809.
[2] Wu et al., Phys. Rev. B 84, 195463 (2011); ibid. B 86, 045456 (2012); ibid. B 88, 125422 (2013).
[3] Wu et al., Phys. Rev. B 86, 165411 (2012)

Keywords: valleytronics, valley-orbit interaction, valley filter, inverse valley-Hall effect, graphene nanowire