Pratama F R, Ukhtary M Shoufie, Saito Riichiro
Department of Physics, Tohoku University, Sendai 980-8578, Japan.
J Phys Condens Matter. 2019 Jul 3;31(26):265701. doi: 10.1088/1361-648X/ab1335. Epub 2019 Mar 25.
We theoretically investigate the optical transition of an electron in graphene that is excited by near-field around a conical Au tip. The interaction between the near-field and the electron is calculated by tight-binding method. In the case of near-field, the wavevector of the electron changes by the optical absorption from the valence band to the conduction band. We show that the change of the wavevector is inversely proportional to the localization width of the near-field, which is given as a function of the distance between the tip and graphene. We calculate the near-field absorption probability as a function of k in the Brillouin zone.
我们从理论上研究了石墨烯中电子的光学跃迁，该跃迁由锥形金尖端周围的近场激发。近场与电子之间的相互作用通过紧束缚方法计算。在近场情况下，电子的波矢通过从价带向导带的光吸收而发生变化。我们表明，波矢的变化与近场的局域宽度成反比，近场的局域宽度是作为尖端与石墨烯之间距离的函数给出的。我们计算了布里渊区中作为波矢(k)的函数的近场吸收概率。
