Electron Optics in Ballistic Graphene
DIPC Seminars
- Speaker
-
Dr. Ming-Hao Liu. Institut fuer Theoretische Physik, Universitaet Regensburg, Germany
- When
-
2016/11/25
13:00 - Place
- Donostia International Physics Center
- Add to calendar
- iCal
Electrons in clean graphene are known to behave like “charged photonsâ€,
exhibiting both electronic and optical properties, due to its celebrated
energy dispersion linear in momentum, providinig an ideal platform for
exploring electron optics. Despite its discovery in 2004, ballistic graphene
devices with micron-scale mean free paths became accessible only recently.
Reliable quantum transport simulations in the ballistic limit for
understanding and predicting high-quality transport experiments have therefore
become increasingly demanded nowadays. In the first part of this talk, an
overview of our recent progress on simulating a variety of ballistic graphene
transport experiments will be given, including Fabry-Pérot interference in
single- [1,2] and bilayer graphene [3], conductance oscillation due to snake
states [4], and guiding of electrons in a few-mode ballistic graphene channel
[5]. Keys to these simulations will be briefly introduced. In the second part
of the talk, our recent proposal for creating and manipulating electron beams
in graphene [6] will be illustrated. The proposed lens composed of a parabolic
pn junction and a point-like source shows unprecedented control over the
electron propagation in ballistic graphene, and will possibly bring the field
of electron optics one step forward.
[1] Rickhaus, P. et al., Nat. Commun. 4 (2013) 2342.
[2] Drienovsky, M. et al., Phys. Rev. B 89 (2014) 115421.
[3] Varlet, A. et al., Phys. Rev. Lett. 113 (2014) 116601.
[4] Rickhaus, P. et al., Nat. Commun. 6 (2015) 6470.
[5] Rickhaus, P. et al., Nano Letters 15 (2015) 5819.
[6] Liu, M.-H., Gorini, C., Richter, K., arXiv:1608.01730.