Gate-tunable Quantum Interferences in Monolayer Graphene PN Junctions

Ballistic Dirac Fermions transport across gate-defined PN junctions exhibits strong dependence on incident angle due to the linear dispersion relationship. Multiple experiments have been performed utilizing the angle-dependence of Klein tunneling, in which novel electron-optics concepts including electron collimation [1] and Veselago lensing [2][3] have been demonstrated. Here we demonstrate preliminary experimental observations of quantum interferences based on these concepts. Preliminary transport data across carefully-engineered PN junctions will be presented and quantitative analysis based on Klein-tunneling probability will also be discussed.

[1] Ke Wang et al, Proc. Nat. Acad. Sci. 116, 6575-6579 (2019.)
[2] Shaowen Chen et al, Science 353, 1522-1525 (2016).
[3] Gil-Ho Lee et al, Nature Physics volume11, 925-929 (2015).