Direct imaging of coherent quantum transport in graphene p-n-p junctions
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Authors
Abstract
We fabricate a graphene p-n-p heterojunction and exploit the coherence of weakly-confined Dirac quasiparticles to resolve the underlying scattering potential using low temperature scanning gate microscopy. The tip-induced perturbation to the heterojunction modifies the condition for resonant scattering, enabling us to detect localized Fabry-Perot cavities from the focal point of halos in scanning gate images. In addition to halos over the bulk we also observe ones spatially registered to the physical edge of the graphene. Guided by quantum transport simulations we attribute these to modified resonant scattering at the edges within elongated cavities that form due to focusing of the electrostatic field.
Description
Keywords
cond-mat.mes-hall, cond-mat.mes-hall
Journal Title
Physical Review B - Condensed Matter and Materials Physics
Conference Name
Journal ISSN
1098-0121
1550-235X
1550-235X
Volume Title
92
Publisher
American Physical Society (APS)
Publisher DOI
Sponsorship
Engineering and Physical Sciences Research Council (EP/I029575/1)
Engineering and Physical Sciences Research Council (EP/L020963/1)
Engineering and Physical Sciences Research Council (EP/L020963/1)
We would like to acknowledge support from EPSRC.