氢吸附调控石墨烯自旋密度的理论研究(英文)
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摘要
采用基于DFT理论的第一性原理计算方法对石墨烯吸附氢的磁性进行研究。首先对石墨烯量子点进行磁性的研究,研究表明边缘用氢钝化的石墨烯量子点所表现出的磁性和石墨烯量子点的切割形状紧密相关,切割形状为矩形的石墨烯量子点表现出反铁磁的性质,切割形状为三角形的石墨烯量子点表现出铁磁的性质。其次对石墨烯晶格吸附氢栅和氢探针所引起的自旋磁性进行计算研究,结果表明通过氢栅的吸附可以改变石墨烯的几何结构和能带结构,石墨烯的形状由二维的平直结构变为三维的起伏结构,石墨烯的带隙从零变为0.214 e V。最后研究氢探针对氢栅的影响,发现氢探针能够改变氢栅附近自旋密度分布,引起自旋干涉现象。我们计算了4个典型的位置A_1、A_2、B_1、B_2,发现不同的探针吸附位置引起不同的自旋干涉,氢栅的自旋密度分布与碳原子自旋密度分布趋势一致,但碳原子的自旋磁矩比氢栅的自旋磁矩大三倍,并且氢探针越靠近氢栅,自旋的干涉效应越明显。这些性质有助于石墨烯在自旋半导体器件、自旋开关等领域中的应用。
Artificial regulation of spin interference in graphene is studied by regulating hydrogen atoms adsorbed on graphene based on density functional theory. When there is a hydrogen raster adsorbed on graphene, the system becomes very spin-sensitive and even an individual additional adatom of hydrogen can act as a probe that stimulates a remarkable interference pattern of spin around the raster. The interference pattern depends on the position of probe with respect to the raster. The model can be used as a signal generator in spintronics or a memory based on spin storage.
Artificial regulation of spin interference in graphene is studied by regulating hydrogen atoms adsorbed on graphene based on density functional theory. When there is a hydrogen raster adsorbed on graphene, the system becomes very spin-sensitive and even an individual additional adatom of hydrogen can act as a probe that stimulates a remarkable interference pattern of spin around the raster. The interference pattern depends on the position of probe with respect to the raster. The model can be used as a signal generator in spintronics or a memory based on spin storage.
引文
1 Wolf S,Awschalom D,Buhrman R,Daughton J,Von Molnar S,Roukes M,Chtchelkanova A Y,Treger D.Science,2001,294,1488.
2 ?uti?I,Fabian J,Sarma S D.Rev Mod Phys,2004,76,323.
3 Nitta J.NTT.Technica.l Review,2004,2,31.
4 Lei T M,Liu J J,Zhang Y M,Guo H,Zhang Z Y.China Phys B,2013,22:117502.
5 Zhang Y P,Yin Y H,Lv H H,Zhang H Y.China Phys B,2014,23:027202.
6 Zhao S Q,Lv Y,Lv W G,Liang W J,Wang E G.China Phys B,2014,23:067305.
7 Ney A,Papakonstantinou P,Kumar A,Shang N-G,Peng N I.Appl Phys Lett,2011,99:102504.
8 Gómez-Santos G,Stauber T.Phys Rev Lett,2011,106:045504.
9 Pesin D,Mac Donald A H.Nature Materials,2012,11:409.
10 Fernández-Rossier J,Palacios J J.Phys Rev Lett,2007,99:177204.
11 Boukhvalov D,Katsnelson M,Lichtenstein A.Phy Rev B,2008,77:035427.
12 Balog R,J?rgensen B,Wells J,L?gsgaard E,Hofmann P,Besenbacher F,Hornek?r L.JACS,2009,131:8744.
13 Patchkovskii S,John S T,Yurchenko S N.Zhechkov L,Heine T,Seifert G.PANS,2005,10210439.
14 Payne M C,Teter M P,Allan D C,Arias T A,Joannopoulos J D.Rev Mod Phys,1992,64:1045.
15 Ceperley D M,Alder B.Phy Rev Lett,1980,45:566.
16 Hamann D,Schlüter M,Chiang C.Phy Rev Lett,1979,43:1494.
2 ?uti?I,Fabian J,Sarma S D.Rev Mod Phys,2004,76,323.
3 Nitta J.NTT.Technica.l Review,2004,2,31.
4 Lei T M,Liu J J,Zhang Y M,Guo H,Zhang Z Y.China Phys B,2013,22:117502.
5 Zhang Y P,Yin Y H,Lv H H,Zhang H Y.China Phys B,2014,23:027202.
6 Zhao S Q,Lv Y,Lv W G,Liang W J,Wang E G.China Phys B,2014,23:067305.
7 Ney A,Papakonstantinou P,Kumar A,Shang N-G,Peng N I.Appl Phys Lett,2011,99:102504.
8 Gómez-Santos G,Stauber T.Phys Rev Lett,2011,106:045504.
9 Pesin D,Mac Donald A H.Nature Materials,2012,11:409.
10 Fernández-Rossier J,Palacios J J.Phys Rev Lett,2007,99:177204.
11 Boukhvalov D,Katsnelson M,Lichtenstein A.Phy Rev B,2008,77:035427.
12 Balog R,J?rgensen B,Wells J,L?gsgaard E,Hofmann P,Besenbacher F,Hornek?r L.JACS,2009,131:8744.
13 Patchkovskii S,John S T,Yurchenko S N.Zhechkov L,Heine T,Seifert G.PANS,2005,10210439.
14 Payne M C,Teter M P,Allan D C,Arias T A,Joannopoulos J D.Rev Mod Phys,1992,64:1045.
15 Ceperley D M,Alder B.Phy Rev Lett,1980,45:566.
16 Hamann D,Schlüter M,Chiang C.Phy Rev Lett,1979,43:1494.