三角形石墨烯量子点阵列的磁电子学特性和磁输运性质

发布时间：2018-04-02 16:18

本文选题：三角形石墨烯纳米片　切入点：一维量子点阵列　出处：《物理学报》2017年13期

【摘要】：基于密度泛函理论的第一性原理计算方法,研究了三角形石墨烯纳米片用不同连接方式拼接而成的四种一维量子点阵列(1D QDAs)的磁电子学性质和磁输运性质.结合能计算表明所有1D QDAs是非常稳定的.特别是研究发现1D QDAs的电子和磁性质不仅依赖于磁性态,也明显依赖于连接方式,如在无磁态时,不同量子点阵列(QDAs)可为金属或窄带隙半导体.在铁磁态时,不同QDAs能为半金属(half-metal)或带隙不同的双极化磁性半导体.而在反铁磁态时,不同QDAs为带隙不等的半导体.这些结果意味着连接方式对有效调控纳米结构电子和磁性质扮演重要的角色.1D QDAs呈现的半金属或双极化磁性半导体性质对于发展磁器件是非常重要的,而这些性质未曾在本征石墨烯纳米带中出现.同时,我们也研究了一种阵列的磁器件特性,发现其拥有完美的(100%)单或双自旋过滤效应,尤其是呈现超过109%的巨磁阻效应.
[Abstract]:Based on the first-principle method of density functional theory (DFT), the magnetoelectronic properties and magnetic transport properties of four kinds of one-dimensional quantum dot arrays (1D QDAss) were studied.The binding energy calculation shows that all 1D QDAs are very stable.In particular, it is found that the electronic and magnetic properties of 1D QDAs depend not only on the magnetic state, but also on the connection mode. For example, in the absence of magnetic state, different QDs can be metal or narrow-band gap semiconductors.In ferromagnetic states, different QDAs energies are half-metal or dual-polarized magnetic semiconductors with different band gaps.However, in antiferromagnetic states, different QDAs are band-gap semiconductors.These results suggest that the connection mode plays an important role in the effective regulation of the electronic and magnetic properties of nanostructures. 1D QDAs presents semimetallic or bipolar magnetic semiconductor properties that are important for the development of magnetic devices.These properties have not been found in intrinsic graphene nanobelts.At the same time, we also study the characteristics of an array of magnetic devices and find that it has a perfect single or double spin filtering effect, especially the giant magnetoresistive effect of over 109%.
【作者单位】：长沙理工大学物理与电子科学学院;
【基金】：国家自然科学基金(批准号:61371065,11674039) 湖南省自然科学基金(批准号:14JJ2076,2015JJ3002,2015JJ2009,2015JJ2013)资助的课题~~
【分类号】：O471.1

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