Tunable laser and photocurrents from linear atomic C chains

TL;DR

This paper models linear atomic carbon chains as tunable laser media and demonstrates their potential for generating photocurrents with laser pulses, highlighting their suitability for light-controlled signal applications.

Contribution

It introduces a tight-binding model for LACCs, showing their tunable laser wavelength range and fast electron dynamics, advancing their application as laser media.

Findings

LACCs can serve as tunable laser media with wavelengths from 321 to 785 nm.

Electrons in LACCs relax to the band bottom within a few picoseconds.

Photocurrents can be generated using dichromatic laser pulses in LACCs.

Abstract

By a tight-binding model, the interaction between linear atomic C chains (LACCs) and short laser pulses was investigated. LACCs were proposed to be used as a medium of laser whose wavelength can be continuously tuned in a range of 321~785 nm. This data should be more accurate than the previous result because pure density functional theory calculation always underestimates the band gap. According to the tight-binding model, the lifetime of conduction band (CB) bottom is about 1.9~2.3 ns. The electrons pumped into the CB will quickly fall to the band bottom in a time of ps due to electron$-$phonon interactions. The above results indicate that LACCs are suitable for laser medium. By {\omega}+ 2{\omega} dichromatic laser pulses, photocurrents can be generated in LACCs, which can be applied as light$-$controlled signals.