Conductance quantization in multiwalled carbon nanotubes

Abstract

Abstract. We present results of carbon nanotube conductance measurements. The experiments were performed using an scanning probe microscope (SPM) system where a carbon nanotube fiber is connected to the SPM tip and then lowered into a liquid mercury contact. Experiments were also performed using a modified transmission electron microscope (TEM) specimen holder supplied with piezo and micrometer positioning system. Thus the contacting process of the nanotubes with the mercury could be monitored while simultaneously recording the conductance. These measurements and observations confirm previously reported conductance quantization (Frank et al.: Science 280, 1744) of the nanotubes while providing additional details concerning the mercury nanotube contacts. We also report conductance versus voltage characteristics of carbon nanotubes.

Giant magnetoresistance of multiwall carbon nanotubes: Modeling the tube/ferromagnetic-electrode burying contact

“…The conductance gets reduced by a factor close to two, very much like in the ferromagnetic computations. More importantly however, this behavior is in qualitative agreement with experimental results 11,23 if we associate the lower and upper bunch of curves in Fig. 5 with the major plateaux of the conductance of MWCNT immersed into Hg.…”

“…The conductance suppression in MWCNTs below the expected value for the infinite homogeneous tube has been experimentally well documented. 11,23 In our model system charge-transfer induced changes in the band structure of the DWCNT lead to a reduction (roughly to 4e 2 /h) of the conductance -as one can see in the upper curves in Fig. 5.…”

Effect of scattering and contacts on current and electrostatics in carbon nanotubes

“…Metallic carbon nanotubes are near ideal conductors of current [1,2,3,4,5]. While a single nanotube can be used as an interconnect in molecular electronics, nanotube arrays have shown promise as more conventional interconnects in conjunction with silicon technology [6,7].…”

“…The non crossing subbands of small diameter nanotubes do not carry current due to their large band gap. In contrast, large diameter nanotubes experimentally show an increase in conductance with applied bias [1,2,12,13]. Reference [14] suggested that as the diameter increases, electrons may tunnel into non crossing subbands, thus causing an increase in differential conductance with applied bias.…”

Buildup of Sn@CNT nanorods by in-situ thermal plasma and the electronic transport behaviors

“…It is confirmed that the single-walled carbon nanotubes (SWCNTs) or their bundles show the classical transport properties such as Coulomb blockade, energy quantization, Luttinger liquid characteristics and ballistic transport [4,5]. It is usually difficult for the multi-walled carbon nanotubes (MWCNTs) to make electrical contact between neighbor graphite layers because the total conductance is significantly limited by the charge carrier transport [6]. Variable range hopping (VRH) conduction, weak localization, resonant tunneling phenomena, universal conductance fluctuations, or Aharanov-Bohm oscillations of magnetoresistance, may appear or become dominant in the electrical transport of MWCNTscontaining systems [7,8].…”