Giant Second Harmonic Generation from Wafer-Scale Aligned Chiral Carbon Nanotubes
Chiral carbon nanotubes (CNTs) are direct-gap semiconductors with optical properties governed by one-dimensional excitons with enormous oscillator strengths. Each species of chiral CNTs has an enantiomeric pair of left- and right-handed CNTs with nearly identical properties, but enantiomer-dependent...
Saved in:
Main Authors | , , , , , , , , , , , , , , , , , , |
---|---|
Format | Journal Article |
Language | English |
Published |
05.07.2024
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Chiral carbon nanotubes (CNTs) are direct-gap semiconductors with optical
properties governed by one-dimensional excitons with enormous oscillator
strengths. Each species of chiral CNTs has an enantiomeric pair of left- and
right-handed CNTs with nearly identical properties, but enantiomer-dependent
phenomena can emerge, especially in nonlinear optical processes. Theoretical
studies have predicted strong second-order nonlinearities for chiral CNTs, but
there has been no experimental verification due to the lack of macroscopically
ordered assemblies of single-enantiomer chiral CNTs. Here for the first time,
we report the synthesis of centimeter-scale films of densely packed and aligned
single-enantiomer chiral CNTs that exhibit micro-fabrication compatibility. We
observe giant second harmonic generation (SHG) emission from the chiral CNT
film, which originates from the intrinsic chirality and inversion symmetry
breaking of the atomic structure of chiral CNTs. The observed value of the
dominant element of the second-order nonlinear optical susceptibility tensor
reaches $1.5\times 10^{3}$ pm/V at a pump wavelength of 1030 nm, corresponding
to the lowest-energy excitonic resonance. Our calculations based on many-body
theory correctly estimate the spectrum and magnitude of such excitonically
enhanced optical nonlinearity. These results are promising for developing
scalable chiral-CNT electronics, nonlinear photonics and photonic quantum
computing. |
---|---|
DOI: | 10.48550/arxiv.2407.04514 |