Non-invasive nanoscale potentiometry and ballistic transport in epigraphene nanoribbons

A. de Cecco (1) , V. S. Prudkovskiy (1, 2) , D. Wander (1) , R. Ganguly (1) , C. Berger (3, 2) , W. de Heer (2) , H. Courtois (1) , C. Winkelmann (1)

1 NEEL - QuNES - Nano-Electronique Quantique et Spectroscopie
2 Georgia Institute of Technology [Atlanta]
3 NEEL - QuantECA - Circuits électroniques quantiques Alpes

The recent observation of non-classical electron transport regimes in two-dimensional materials has called for new high-resolution non-invasive techniques to locally probe electronic properties. We introduce a novel hybrid scanning probe technique to map the local resistance and electrochemical potential with nm-and µV resolution, and we apply it to study epigraphene nanoribbons grown on the sidewalls of SiC sub-strate steps. Remarkably, the potential drop is non uniform along the ribbons, and µm-long segments show no potential variation with distance. The potential maps are in excellent agreement with measurements of the local resistance. This reveals ballistic transport (removed "in ambient conditions"), compatible with micrometer-long room-temperature electronic mean free paths.

Mots clés: Metrics & More Article Recommendations Epigraphene; graphene nanoribbons; ballistic transport; scanning tunneling potentiometry

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

A. de Cecco, V. S. Prudkovskiy, D. Wander, R. Ganguly, C. Berger, et al.. Non-invasive nanoscale potentiometry and ballistic transport in epigraphene nanoribbons. Nano Letters, 2020, 20 (5), pp.3786-3790. ⟨10.1021/acs.nanolett.0c00838⟩. ⟨hal-02615492⟩