TY  - JOUR
AU  - Yang, Y.
AU  - Fedorov, G.
AU  - Shafranjuk, S. E.
AU  - Klapwijk, T. M.
AU  - Cooper, B. K.
AU  - Lewis, R. M.
AU  - Lobb, C. J.
AU  - Barbara, P.
PY  - 2015
DA  - 2015//
TI  - Electronic transport and possible superconductivity at Van Hove singularities in carbon nanotubes
T2  - Nano Lett.
JO  - Nano Lett.
SP  - 7859
EP  - 7866
VL  - 15
IS  - 12
KW  - carbon nanotubes
KW  - CNT
KW  - tunable superconductivity
KW  - van Hove singularities
AB  - Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube.
SN  - 1530-6984
UR  - http://www.ncbi.nlm.nih.gov/pubmed/26506109
UR  - https://doi.org/10.1021/acs.nanolett.5b02564
DO  - 10.1021/acs.nanolett.5b02564
N1  - PMID:26506109; Suuplementary info (attached to pdf) DOI: 10.1021/acs.nanolett.5b02564
ID  - Yang_etal2015
ER  -