On the amplification of acoustic phonons in carbon nanotube

Abstract

We present a theoretical study of acoustic phonons amplification in Carbon Nanotubes (CNT). The phenomenon is via Cerenkov emission (CE) of acoustic phonons using intraband transitions proposed by Mensah et. al.,~\cite{1} in Semiconductor Superlattices (SSL) and confirmed in ~\cite{2}. From this, an asymmetric graph of ${\Gamma }^{CNT}$ on $\frac{V_d}{V_s}$ and $\Omega \tau$ were obtained where amplification (${\Gamma }_{amp}^{CNT}$) $>>$ absorption (${\Gamma }_{abs}^{CNT}$). The ratio, $\frac{|{\Gamma }_{amp}^{CNT}|}{|{\Gamma }_{abs}^{CNT}|}\approx 3.5$, at $V_d=1.02V_s$, ${\omega }_q=3.0\mathrm{THz}$ and $T=85K$ for scattering angle $\theta >0$ . A threshold field at which ${\Gamma }_{abs}^{CNT}$ switches over to ${\Gamma }_{amp}^{CNT}$ was calculated to be $E_z^{dc}=6.2\times 10^{3}V/m$. This field is far less than that deduced using Bloch-Type Oscillation (BTO)~\cite{3} which is $E_{BTO}^{dc}=3.0\times 10^{5}V/m$. The obtained ${\Gamma }_{amp}^{CNT}$ would enable the use of CNT for the production of SASER.

12 pages, 2 figures

References in corpus (3)

• Acoustoelectric Effect in degenerate Carbon Nanotube
• Negative Differential Conductivity in Carbon Nanotubes in the Presence of an External Electric Field
• Amplification of acoustic phonons in superlattice