Anderson localization in carbon nanotubes: defect density and temperature effects.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Single-walled carbon nanotubes (SWCNTs) are promising materials for electronic applications.
• Understanding defect impacts on SWCNT conductivity is crucial for device reliability.
• Irradiation can introduce defects, altering electronic transport properties.

Purpose of the Study:

• To investigate the effect of irradiation-induced defects on the conducting properties of (10,10) SWCNTs.
• To analyze the influence of temperature on these defect-induced changes.
• To elucidate the fundamental mechanisms governing conductivity in defective SWCNTs.

Main Methods:

• Utilized a first-principles computational approach.
• Simulated the impact of divacancies on differential conductance.
• Analyzed the energy dependence of conductance and transport channels.
• Investigated Anderson localization effects and resistance scaling with defect density.
• Examined temperature effects (15-65 K) on conductance fluctuations and resistivity.

Main Results:

• Divacancies strongly modify the energy dependence of differential conductance.
• The number of contributing transport channels decreases from two (ideal) to one.
• A small concentration of divacancies (5-9) induces significant Anderson localization.
• A near-universal resistance curve emerges as a function of defect number.
• Low temperatures (15-65 K) smooth conductance fluctuations without disrupting exponential resistivity dependence on length.

Conclusions:

• Divacancies are critical defects affecting SWCNT conductivity.
• Anderson localization becomes prominent with minimal defect introduction.
• Temperature plays a role in stabilizing transport properties at low ranges.
• First-principles calculations provide key insights into defect-driven electronic behavior in SWCNTs.