Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Phys Rev Lett. 2009 Oct 30;103(18):187204. doi: 10.1103/PhysRevLett.103.187204.
We predict a magnetoelectric (ME) effect in graphene nanoribbons on silicon substrates by first-principles calculations. It is shown that a bias voltage can produce strong linear ME effect by driving charge transfer between the nanoribbons and substrate, thus tuning the exchange splitting of magnetic edge states; moreover, the bias induced n-to-p-type transition in the ribbon layer can switch the ME coefficient from negative to positive due to the unique symmetry of band structures. This mechanism is proven to be robust against variations in material and physical configurations, thus opening a new avenue for ME coupling in metal-free magnet systems of practical importance.
我们通过第一性原理计算预测了硅衬底上石墨烯纳米带的磁电（ME）效应。结果表明，通过驱动纳米带和衬底之间的电荷转移，偏置电压可以产生很强的线性 ME 效应，从而调节磁性边缘态的交换劈裂；此外，由于能带结构的独特对称性，偏置诱导的带状层中 n 型到 p 型的转变可以使 ME 系数从负变为正。该机制被证明对材料和物理构型的变化具有鲁棒性，从而为具有实际重要性的无金属磁体系统中的 ME 耦合开辟了新途径。
