arXiv subjects

Niels Vandecasteele

Publications and source records attributed to Niels Vandecasteele.

2 recordsLinked to original sources

arXiv2010

Current-voltage characteristics of graphene devices: interplay between Zener-Klein tunneling and defects

We report a theoretical/experimental study of current-voltage characteristics (I-V) of graphene devices near the Dirac point. The I-V can be described by a power law (I \propto V^α, with 1< α<= 1.5). The exponent is higher when the mobility is lower. This superlinear I-V is interpreted in terms of the interplay between Zener-Klein transport, that is tunneling between different energy bands, and defect scattering. Surprisingly, the Zener-Klein tunneling is made visible by the presence of defects.

cond-mat.mtrl-sci↗

arXiv2009

Boosting electronic transport in carbon nanotubes by isotopic disorder

The current/voltage curve of metallic carbon nanotubes (CNTs) displays at high bias a sudden increase of the resistivity due to the scattering of electrons with phonons having an anomalously-high population (hot phonons). Here, we show that it is possible to improve the electrical performances of metallic CNTs by C13 isotope enrichment. In fact, isotopic disorder creates additional channels for the hot-phonon deexcitation, reduces their population and, thus, the nanotube high-bias differential-resistance. This is an extraordinary case where disorder improves the electronic transport.

cond-mat.mtrl-sci↗