具有分离门的电抽运多层石墨烯负动态电导率的理论研究

本文提出了具有分离门的电抽运多层石墨烯结构, 建立了电诱导n-i-p结的理论模型, 计算了集居数反转的条件下与带内和带间跃迁相关的动态电导率, 讨论了偏置电压、门电压、石墨烯层数以及动量弛豫时间对动态电导率的影响. 结果表明, 在一定条件下, 动态电导率的实部在太赫兹范围内可以是负的, 即带间辐射大于带内吸收, 论证了电抽运多层石墨烯结构作为产生太赫兹相干光源的激活物质的可行性.

Theory research of negative dynamic conductivity in electrically pumped multiple graphene layer structures with split gates

The negative dynamic conductivity of graphene in THz range makes it to be a promise medium in THz radiation and amplification. This paper proposes electrically pumped multiple graphene layer structures with split gates, sets up the theory model of electrically induced n-i-p junction, calculates the ac conductivity associated with the interband and intraband transitions under the conditions of population inversion, discusses the bias voltage, gate voltage, number of graphene layers and the momentum relaxation time dependences of ac conductivity. It is shown that the real part of dynamic conductivity within terahertz range can be negative in certain conditions, namely, interband radiation is greater than the intraband absorption, which demonstrates the feasibility of taking electrically pumped multiple graphene layer structures with split gates as an active medium in radiating terahertz coherent source.