Superconductivity in Bundles of Double-Wall Carbon Nanotubes

Abstract

We present electrical and thermal specific heat measurements that show superconductivity in double-wall carbon nanotube (DWCNT) bundles. Clear evidence, comprising a resistance drop as a function of temperature, magnetoresistance and differential resistance signature of the supercurrent, suggest an intrinsic superconducting transition below 6.8 K for one particular sample. Additional electrical data not only confirm the existence of superconductivity, but also indicate the Tc distribution that can arise from the diversity in the diameter and chirality of the DWCNTs. A broad superconducting anomaly is observed in the specific heat of a bulk DWCNT sample, which yields a Tc distribution that correlates well with the range of the distribution obtained from the electrical data. As quasi one dimensionality of the DWCNTs dictates the existence of electronic density of state peaks, confirmation of superconductivity in this material system opens the exciting possibility of tuning the Tc through the application of a gate voltage.

Double-walled carbon nanotubes: synthesis, structural characterization, and application

“…The superconductivity of selective samples of DWCNT bundles, where each nanotube is packed in a hexagonal form, was verified by measuring electrical and thermal specific heat measurements [36]. A resistance drop as a function of temperature, magnetoresistance, and the differential resistance signature of the supercurrent supports an intrinsic superconducting transition below 6.8 K for a single DWCNT bundle.…”

The role of the coherence length for the establishment of global phase coherence in arrays of ultra-thin superconducting nanowires

“…The zero-field specific heat data allow us to derive the Tc distribution of NbN-SBA-15, as described in detail in Ref. [5,8,47]. In Fig.…”

“…Such nanowires or linear atomic chains can either be realized in the form of individual free-standing nanowires [2,3], or can be arranged to form an array of parallel 1D nano-elements [1,[4][5][6][7]. The latter was realized in the form of artificially grown nanostructures [1,5,6,8,9] or found in intrinsic quasi-1D superconducting materials such as Tl2Mo6Se6 [10] or Sc3CoC4 [11,12]. The latter contain many parallel conducting 1D atomic chains separated by either insulating layers or a non-superconducting metallic host.…”

A Review of Double-Walled and Triple-Walled Carbon Nanotube Synthesis and Applications

“…In the past two decades, major progress has been made first towards synthesizing or isolating semiconducting nanotubes, metallic nanotubes and later (n, m)-specific samples. These major advances give an additional boost to carbon nanotube science [21][22][23][24][25][26][27][28][29]. These advances brought along the capability of synthesizing better SWNT (n, m)-specific samples and also provide more capability for synthesizing DWNT and TWNT samples containing either only DWNTs or only TWNTs [21][22][23][24][25][26][27][28][29].…”