Quantum Transport in Graphene near the Dirac Point

狄拉克点附近石墨烯的量子传输

• 批准号: 171275106
• 负责人: Professor Dr. Piet W. Brouwer
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/171275106?language=en
• 关键词: Quantum; Transport; Graphene; near; Dirac

Graphene, a single layer of graphite, is a newly discovered material with remarkable electronic properties. Charge carriers in graphene are described by the relativistic Dirac equation, instead of the Schroedinger equation that is used for other two-dimensional electron gases. Differences between graphene and hitherto known two-dimensional electron systems are most pronounced at the "Dirac point'', when the Fermi energy coincides with the zero energy point in the Dirac equation. This proposal addresses three aspects of transport near the Dirac point: Time-dependent transport and the development of a semiclassical theory for gate-defined quantum dots in an otherwise undoped graphene sheet, mixing of co-propagating edge states at a graphene p-n junction in a quantizing magnetic field, including energy dependence and interaction effects, and one-parameter scaling for disordered graphene in the vicinity of the Dirac point, where the conductivity without disorder is finite but small, sigma = 4 e^2/pi h. The gate-defined quantum dots are naturally connected to the ``electron/hole puddles'', which form in graphene at the Dirac point in the presence of a strong random potential and, in that case, determine the conductivity of graphene.

石墨烯是一种单层石墨，是一种新发现的具有显著电子特性的材料。石墨烯中的载流子由相对论性狄拉克方程描述，而不是用于其他二维电子气体的薛定谔方程。石墨烯与迄今为止已知的二维电子系统之间的差异在“狄拉克点”最为明显，此时费米能量与狄拉克方程中的零能量点重合。本方案涉及Dirac点附近交通的三个方面：时间相关输运和未掺杂石墨烯片中门定义量子点的半经典理论的发展，量子化磁场中石墨烯p-n结共传播边缘态的混合，包括能量依赖和相互作用效应，以及狄拉克点附近无序石墨烯的单参数标度，其中无无序的电导率有限但很小。σ = 4 e^2/pi h。门定义的量子点自然地与“电子/空穴水坑”相连，这些水坑在石墨烯的狄拉克点形成，存在强大的随机电位，在这种情况下，决定了石墨烯的导电性。