Strong Charge-Transfer Excitonic Effects and the Bose-Einstein Exciton Condensate in Graphane
Strong Charge-Transfer Excitonic Effects and the Bose-Einstein Exciton Condensate in Graphane
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DOI：
10.1103/physrevlett.104.226804
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发表时间：
2010-06-01
影响因子：
8.6
通讯作者：
Rubio, Angel
中科院分区：
文献类型：
--
作者：
Cudazzo, Pierluigi;Attaccalite, Claudio;Rubio, Angel
使用第一性原理多体理论方法（GW+Bethe-Salpeter方程），我们证明了在二维电介质中，石墨烷的光学性质是由增强的电子关联所控制的局部电荷转移激发所主导的。强的电子-空穴相互作用导致小半径束缚激子的出现，其中电子和空穴在空间上分离，它们分别位于面外和面内。这种束缚激子的存在打开了通往石墨烷中的激子玻色-爱因斯坦凝聚体的道路，可以在实验中观察到。
Using first principles many-body theory methods (GW+Bethe-Salpeter equation) we demonstrate that the optical properties of graphane are dominated by localized charge-transfer excitations governed by enhanced electron correlations in a two-dimensional dielectric medium. Strong electron-hole interaction leads to the appearance of small radius bound excitons with spatially separated electron and hole, which are localized out of plane and in plane, respectively. The presence of such bound excitons opens the path towards an excitonic Bose-Einstein condensate in graphane that can be observed experimentally.