标题： 石墨烯中Rashba自旋-轨道耦合的最小电导率的有限尺寸效应 显示英文标题

标题： Finite-size effects on the minimal conductivity in graphene with Rashba spin-orbit coupling

摘要： 我们从理论上研究了在Rashba自旋-轨道耦合存在下单层石墨烯的最小电导率。 Rashba自旋-轨道相互作用导致低能带发生三角形畸变，对于能量小于Lifshitz能量的情况，费米圆分解为部分，形成四个独立的狄拉克锥。 我们在连续模型和紧束缚模型中，利用Landauer--Büttiker形式，在长度为$L$、宽度为$W$的理想条带中计算最小电导率。 我们表明，由于与不同狄拉克锥相关的态的干涉，最小电导率取决于样品和探测电极的相对取向。 我们还探讨了有限系统尺寸的影响，并发现与无限宽样品相比，最小电导率可以降低。 显示英文摘要

摘要： We study theoretically the minimal conductivity of monolayer graphene in the presence of Rashba spin-orbit coupling. The Rashba spin-orbit interaction causes the low-energy bands to undergo trigonal-warping deformation and for energies smaller than the Lifshitz energy, the Fermi circle breaks up into parts, forming four separate Dirac cones. We calculate the minimal conductivity for an ideal strip of length $L$ and width $W$ within the Landauer--B\"uttiker formalism in a continuum and in a tight binding model. We show that the minimal conductivity depends on the relative orientation of the sample and the probing electrodes due to the interference of states related to different Dirac cones. We also explore the effects of finite system size and find that the minimal conductivity can be lowered compared to that of an infinitely wide sample.