简并能量色散对石墨烯中超声波放大的影响
Amplification of Hypersound in Graphene with degenerate energy dispersion
摘要：
研究了具有简并能量色散$\varepsilon(p)$的石墨烯在费米能级附近声子的超声波放大/吸收。对于$k_βT << 1$和$ql >> 1$，研究了吸收系数$Γ/Γ_0$对${V_D\over V_s}$的依赖性，其中结果满足切伦科夫效应。也就是说，当${V_D\over V_s} > 1$时，获得放大，但对于${V_D\over V_s} < 1$，获得吸收，这可能导致石墨烯中的声电效应（AE）。观察到$Γ/Γ_0$对$ω_q$的线性依赖性，其中通过Weinrich关系获得的结果定性地与实验观察到的石墨烯中的声电电流一致。有趣的是，从本研究中注意到，对于$V_D = 1.1ms^{-1}$，可以获得高于$10THz$的频率。该研究允许使用石墨烯作为超声波声子激光器（SASER）。
英文摘要：
Hypersound amplification/absorption of acoustic phonons in Graphene with degenerate energy dispersion $\varepsilon(p)$ near the Fermi level was theoretically studied. For $k_βT << 1$ and $ql >> 1$, the dependence of the absorption coefficient $Γ/Γ_0$ on ${V_D\over V_s}$ was studied where the results satisfied the Cerenkov effect. That is when ${V_D\over V_s} > 1$, an amplification was obtained but for ${V_D\over V_s} < 1$, an absorption was obtained which could lead to Acoustoelectric Effect (AE) in Graphene. A linear dependence of the $Γ/Γ_0$ on $ω_q$ was observed where the result obtianed qualitatively agreed with an experimentally observed acoustoelectric current in Graphene via the Weinrich relation. It is interesting to note from this study that, frequencies above $10THz$ can be attained for $V_D = 1.1ms^{-1}$. This study permit the use of Graphene as hypersound phonon laser (SASER).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
