论文标题
在硅烯中热零毛发的功率损失及其与石墨烯几乎相等的功率
Power loss of hot Dirac fermions in silicene and its near equivalence with graphene
论文作者
论文摘要
通过耦合到固有的插图和Intervalley声音和光学声子的耦合，在硅中分析了功率损失$ p $，这是电子温度$ t_e $和密度$ n_s $的函数。在非常低的$ t_e $下，发现功率耗散遵循Bloch-GrüneisenPowerLaw $ \ propto t_e^4 $和$ n_s^{ - 0.5} $，如在石墨烯中，对于$ t_e \ lyssim20-30 $ k，由于Intravalley Phavalley Ecout ocous ocous ocous ocous satpers和$ t_e \ lyssim20-30 $ k，主要的功率损失是主要的。另一方面，与石墨烯不同，与$ \ sim $$ 30 $ k的温度低至$ \ sim $$ 30 $ k的温度低至$ \ sim $ t_e \ gtrsim200 $ k的温度下，无分散的低能声音声子开始占主导地位。总功率损耗以$ t_e $增加，值为$ \ sim $$ 10^{10} $ ev/s $ 300 $ k，这与石墨烯中的数量级相同。 Interavalley声音子造成的功率损失随$ n_s $在较高$ t_e $时增加，而由于Intervalley声音和光学声子引起的，被发现独立于$ n_s $。有趣的是，硅的能源放松时间比石墨烯高约4美元。因此，硅在其在煤层和量热计中的应用可能比石墨烯优于石墨烯。电源传输到表面光学声子$ p _ {\ text {so}} $也被研究为$ t_e $的函数，而在al $ _2 $ o $ _3 $ bistrate上的硅$ n_s $ for Silicene的函数，发现它比interinsic Phonon贡献更大。讨论了基板工程以减少$ p _ {\ text {so}} $。
The power loss $P$ of hot Dirac fermions through the coupling to the intrinsic intravalley and intervalley acoustic and optical phonons is analytically investigated in silicene as a function of electron temperature $T_e$ and density $n_s$. At very low $T_e$, the power dissipation is found to follow the Bloch-Grüneisen power-law $\propto T_e^4$ and $n_s^{-0.5}$, as in graphene, and for $T_e \lesssim20-30$ K, the power loss is predominantly due to the intravalley acoustic phonon scattering. On the other hand, dispersionless low energy intervalley acoustic phonons begin to dominate the power transfer at temperatures as low as $\sim$$30$ K, and optical phonons dominate at $T_e \gtrsim200$ K, unlike the graphene. The total power loss increases with $T_e$ with a value of $\sim$$10^{10}$ eV/s at $300$ K, which is the same order of magnitude as in graphene. The power loss due to intravalley acoustic phonons increases with $n_s$ at higher $T_e$, whereas due to the intervalley acoustic and optical phonons is found to be independent of $n_s$. Interestingly, the energy relaxation time in silicene is about $4$ times higher than that in graphene. For this reason, silicene may be superior over graphene for its applications in bolometers and calorimeters. Power transfer to the surface optical phonons $P_{\text{SO}}$ is also studied as a function of $T_e$ and $n_s$ for silicene on Al$_2$O$_3$ substrate and it is found to be greater than the intrinsic phonon contribution at higher $T_e$. Substrate engineering is discussed to reduce $P_{\text{SO}}$.
