TY  - JOUR
AU  - Dauber, Jan
AU  - Oellers, Martin
AU  - Venn, Florian
AU  - Epping, Alexander
AU  - Watanabe, Kenji
AU  - Taniguchi, Takashi
AU  - Hassler, Fabian
AU  - Stampfer, Christoph
TI  - Aharonov-Bohm oscillations and magnetic focusing in ballistic graphene rings
JO  - Physical review / B
VL  - 96
IS  - 20
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2020-02432
SP  - 205407
PY  - 2017
AB  - We present low-temperature magnetotransport measurements on graphene rings encapsulated in hexagonal boron nitride. We investigate phase-coherent transport and show Aharonov-Bohm (AB) oscillations in quasiballistic graphene rings with hard confinement. In particular, we report on the observation of h/e,h/2e, and h/3e conductance oscillations. Moreover we show signatures of magnetic focusing effects at small magnetic fields confirming ballistic transport. We perform tight-binding calculations which allow us to reproduce all significant features of our experimental findings and enable a deeper understanding of the underlying physics. Finally, we report on the observation of the AB conductance oscillations in the quantum Hall regime at reasonable high magnetic fields, where we find regions with enhanced AB oscillation visibility with values up to 0.7%. These oscillations are well explained by taking disorder into account allowing for a coexistence of hard- and soft-wall confinement.
LB  - PUB:(DE-HGF)16
C6  - pmid:29116592
UR  - <Go to ISI:>//WOS:000414333700005
DO  - DOI:10.1103/PhysRevB.96.205407
UR  - https://juser.fz-juelich.de/record/877734
ER  -