[Zurück]

N. Freitag, P. Nemes-Incze, L. Chizhova, F. Libisch, C. Woods, R. Gorbachev, Y. Cao, A. Geim, K. Novoselov, J. Burgdörfer, M. Morgenstern:
"Magnetically confined quantum dots in graphene revealed by scanning tunneling spectroscopy";
Poster: International Winter School of Properties of Novel Materials 2016, Kirchberg in Tirol; 13.02.2016 - 20.02.2016.

Confining graphene´s chiral massless charge carriers by carving out nano-structures
to circumvent Klein-tunneling suffers from disordered edges, impeding the control of
the quasi-relativistic particles. Here, we use the electrostatic potential of an STM tip
in combination with an homogeneous magnetic field to confine electrons in graphene
without edges[1].
The confinement becomes visible as a fourfold charging sequence at B > 2T, as
expected from valley and spin degeneracy. Up to 40 charging peaks are observed
in the hole and electron sector. The deduced charging energy range is 5 − 10meV.
Characteristic spatial charging patterns, created by potential modulations of the
commensurate G on BN[2], are found.
[1] G. Giavaras and F. Nori, PRB 85, 165446 (2012)
[2] C. R. Woods et al., Nat. Phys. 10(6), 451-456 (2014)

Graphene, Quantum dots, Valleytronics