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Simultaneous Synthesis of Single-walled Carbon Nanotubes and Graphene in a Magnetically-enhanced Arc Plasma
Published on: February 2, 2012
Second harmonic generation in carbon nanotubes induced by transversal electrostatic field
Mads Lund Trolle1, Thomas Garm Pedersen
1Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg East, Denmark. mlt@nano.aau.dk
Summary
Applying an external voltage to carbon nanotubes (CNTs) can induce second harmonic generation (SHG), a nonlinear optical effect. This work calculates the SHG signal from CNTs under transversal electric fields.
Area of Science:
- Condensed matter physics
- Materials science
- Nanotechnology
Background:
- Carbon nanotubes (CNTs) with inversion symmetry, like armchair and zigzag types, intrinsically lack second-order nonlinear optical responses such as second harmonic generation (SHG).
- Breaking inversion symmetry is crucial for inducing even-order nonlinearities in materials.
Purpose of the Study:
- To investigate the feasibility of inducing and tuning second harmonic generation (SHG) in carbon nanotubes (CNTs) by applying external electric fields.
- To calculate the SHG signal from CNTs subjected to transversal electric fields.
Main Methods:
- Utilizing a tight-binding model to simulate the electronic structure and optical properties of CNTs.
- Calculating the second harmonic generation (SHG) signal under the influence of transversally applied electric fields.
Main Results:
- Demonstrated that breaking the inversion symmetry of CNTs with an external transversal electric field induces a second harmonic response.
- Showed that chiral CNTs, which possess an intrinsic response, exhibit additional non-vanishing second harmonic tensor elements when subjected to external fields.
- The proposed methods suggest possibilities for tunable SHG in CNTs through various experimental setups.
Conclusions:
- External electric fields offer a viable method to induce and control second harmonic generation (SHG) in carbon nanotubes (CNTs).
- This research opens avenues for developing novel nonlinear optical devices based on CNTs with tunable properties.
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