Probing nonlinearities in carbyne with undetected photons at nanoscale

This project focuses on developing a nanoscale mid-infrared (MIR) spectrometer with sub-20 nm resolution for studying confined carbyne, a one-dimensional linear carbon chain within a carbon nanotube. By using this spectrometer, we will investigate confined carbyne's optical properties and structural nonlinearities and explore its potential for mid-IR to visible light transduction.

The proposed approach combines MIR spectroscopy and near-field scanning optical microscopy, which uses a nanostructured tip to interact with the sample. This innovative MIR spectrometer will enable precise measurements of the vibrational properties of nanostructured materials at a resolution of less than 20 nm.

Unlike traditional characterization methods like Raman spectroscopy, MIR spectroscopy can identify structural nonlinearities in confined carbyne chains like chain bending, discontinuity, terminations, and the existence of its elusive metallic phases. These findings will contribute to understanding carbyne's thermal and electron conductivity properties and its potential as a cutting-edge compound for optoelectronic applications.

The project further aims to explore to the use of confined carbyne as for molecular MIR to visible light transduction. This involves resonantly exciting carbyne vibrations with MIR photons and probing transduced visible light with Raman scattering. Due to the superior Raman cross section of confined carbyne, this project has the potential to lay the groundwork for carbyne-based high-performance MIR detectors.