Tsaousidou Margarita, Kubakaddi Shrishail S
Materials Science Department, University of Patras, 26 504 Patras, Greece.
Department of Physics, K.L.E. Technological University, Hubballi 580 031, Karnataka, India.
Materials (Basel). 2023 Mar 12;16(6):2274. doi: 10.3390/ma16062274.
We present a theoretical model for the calculation of the energy loss rate (ELR) of hot electrons in a monolayer graphene due to their coupling with acoustic phonons at high perpendicular magnetic fields. Electrons interact with both transverse acoustic (TA) and longitudinal acoustic (LA) phonons. Numerical simulations of the ELR are performed as a function of the magnetic field, the electron temperature, the electron density, and the Landau level broadening. We find robust oscillations of the ELR as a function of the filling factor ν that originate from the oscillating density of states at the Fermi level. Screening effects on the deformation potential coupling are taken into account, and it is found that they lead to a significant reduction of ELR, especially, at low electron temperatures, Te, and high magnetic fields. At temperatures much lower than the Bloch-Grüneisen temperature, the ELR shows a Te4 dependence that is related to the unscreened electron interaction with TA acoustic phonons. Finally, our theoretical model is compared with existing experimental results and a very good quantitative agreement is found.
我们提出了一个理论模型，用于计算在高垂直磁场下单层石墨烯中热电子与声子耦合导致的能量损失率（ELR）。电子与横向声学（TA）声子和纵向声学（LA）声子都相互作用。作为磁场、电子温度、电子密度和朗道能级展宽的函数，对ELR进行了数值模拟。我们发现ELR作为填充因子ν的函数存在强烈振荡，这源于费米能级处振荡的态密度。考虑了对形变势耦合的屏蔽效应，发现它们会导致ELR显著降低，特别是在低电子温度Te和高磁场下。在远低于布洛赫 - 格林艾森温度的温度下，ELR呈现出Te4依赖性，这与未屏蔽的电子与TA声学声子的相互作用有关。最后，将我们的理论模型与现有的实验结果进行了比较，发现了非常好的定量一致性。
