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., [1] in Semiconductor Superlattices (SSL) and confirmed in [2]. From this, an asymmetric graph of ΓCNT on Vd and Ωτ were obtained where amplification (ΓCNT) >> absorption (ΓCNT ). The ratio,|ΓCNT ||ΓCNT|≈ 3.5, at Vd = 1.02Vs, ωq = 3.0 THz and T = 85 K for scattering angle θ > 0 . A threshold field at which Γ CNT abs switches over to Γ CNT amp was calculated to be E Dc z = 6.2 × 103V/m. This field is far less than that deduced using Bloch Type Oscillation (BTO) [3] which is E dc O = 3.0 × 105 V/m. The obtained ΓCNT amp would enable the use of CNT for the production of SASER