Thermoelectric Amplification of Phonons in Graphene

Abstract

Amplification of acoustic phonons due to an external temperature gredient ($\nabla T$) in Graphene was studied theoretically. The threshold temperature gradient $(\nabla T{)}_0^g$ at which absorption switches over to amplification in Graphene was evaluated at various frequencies ${\omega }_q$ and temperatures $T$. For $T=77K$ and frequency ${\omega }_q=12THz$, $(\nabla T{)}_0^g=0.37K{m}^{-1}$. The calculation was done in the regime at $ql>>1$. The dependence of the normalized ($\Gamma /{\Gamma }_0$) on the frequency ${\omega }_q$ and the temperature gradient $(\nabla T/T)$ are evaluated numerically and presented graphically. The calculated $(\nabla T{)}_0^g$ for Graphene is lower than that obtained for homogeneous semiconductors ($n-InSb$) $(\nabla T{)}_0^{hom}\approx 10^{3}Kc{m}^{-1}$, Superlattices $(\nabla T{)}_0^{SL}=384Kc{m}^{-1}$, Cylindrical Quantum Wire $(\nabla T{)}_0^{cqw}\approx 10^{2}Kc{m}^{-1}$. This makes Graphene a much better material for thermoelectric phonon amplifier.

12 Pages, 6 figures

References in corpus (3)

• The electronic properties of graphene
• Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
• Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene

Cited by in corpus (1)

• Acoustoelectric current in graphene due to electron deformation potential and piezoelectric phonon couplings