arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0911.4431cond-mat.mes-hall
收藏

石墨烯纳米带中的含时输运

Time-dependent transport in graphene nanoribbons

E. Perfetto, G. Stefanucci, M. Cini

摘要:

我们从理论上研究了金属石墨烯纳米带在突然开启偏置电压$V$后随时间变化的弹道输运。该带被分成三个不同的区域,即两个半无限石墨烯引线和长度为$L$的中心部分,在该中心部分上,偏压线性下降,并且在该中心部分处计算电流。我们表明,在早期的瞬态时间的系统表现得像一个石墨烯散装的影响下,一个均匀的电场$E=V/L$。在未掺杂的系统中,电流不随时间线性增长,而是显著地达到具有直流电导率$σ_{1}=πe^{2}/2h$的临时平台,这与二维石墨烯的最小电导率一致。在$L/v_{F}$($v_{F}$是费米速度)级的时间之后,电流离开第一平台并在其最终稳态值处饱和,具有有限宽度的金属纳米带的典型电导率$σ_{2}=2e^{2}/h$。

英文摘要:

We theoretically investigate the time-dependent ballistic transport in metallic graphene nanoribbons after the sudden switch-on of a bias voltage $V$. The ribbon is divided in three different regions, namely two semi-infinite graphenic leads and a central part of length $L$, across which the bias drops linearly and where the current is calculated. We show that during the early transient time the system behaves like a graphene bulk under the influence of a uniform electric field $E=V/L$. In the undoped system the current does not grow linearly in time but remarkably reaches a temporary plateau with dc conductivity $σ_{1}=πe^{2}/2h$, which coincides with the minimal conductivity of two-dimensional graphene. After a time of order $L/v_{F}$ ($v_{F}$ being the Fermi velocity) the current departs from the first plateau and saturates at its final steady state value with conductivity $σ_{2}=2e^{2}/h$ typical of metallic nanoribbons of finite width.

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。

↑