Fine structure constant defines visual transparency of graphene
Fine structure constant defines visual transparency of graphene
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DOI：
10.1126/science.1156965
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发表时间：
2008-06-06
期刊：
影响因子：
56.9
通讯作者：
Geim, A. K.
中科院分区：
文献类型：
--
作者：
Nair, R. R.;Blake, P.;Geim, A. K.
在凝聚态物理学中，很少有现象只由基本常数定义，而不依赖于材料参数。例如电阻率量子h/e2（h是普朗克常数，e是电子电荷），出现在各种传输实验中，磁通量量子h/e在超导物理学中起着重要作用。总的来说，需要精密的设施和特殊的测量条件来观察这些现象。我们表明，悬浮石墨烯的不透明度仅由精细结构常数a = e2/hc定义 1/137（其中c是光速），描述光和相对论电子之间耦合的参数，传统上与量子电动力学而不是材料科学有关。尽管只有一个原子厚，石墨烯被发现吸收入射白色光的显着（pa = 2.3%）部分，石墨烯的独特的电子结构的结果。
There are few phenomena in condensed matter physics that are defined only by the fundamental constants and do not depend on material parameters. Examples are the resistivity quantum, h/e2 (h is Planck's constant and e the electron charge), that appears in a variety of transport experiments and the magnetic flux quantum, h/e, playing an important role in the physics of superconductivity. By and large, sophisticated facilities and special measurement conditions are required to observe any of these phenomena. We show that the opacity of suspended graphene is defined solely by the fine structure constant, a = e2/hc 1/137 (where c is the speed of light), the parameter that describes coupling between light and relativistic electrons and that is traditionally associated with quantum electrodynamics rather than materials science. Despite being only one atom thick, graphene is found to absorb a significant (pa = 2.3%) fraction of incident white light, a consequence of graphene's unique electronic structure.