Katow Hiroki, Akashi Ryosuke, Miyamoto Yoshiyuki, Tsuneyuki Shinji
Photon Science Center, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Phys Rev Lett. 2022 Jul 22;129(4):047401. doi: 10.1103/PhysRevLett.129.047401.
Recent studies on excitons in two-dimensional materials have been widely conducted for their potential usages for novel electronic and optical devices. Especially, sophisticated manipulation techniques of quantum degrees of freedom of excitons are in demand. In this Letter we propose a technique of forming an optical dipole trap for excitons in graphane, a two-dimensional wide gap semiconductor, based on first-principles calculations. We develop a first-principles method to evaluate the transition dipole matrix between excitonic states and combine it with the density functional theory and GW+BSE calculations. We reveal that in graphane the huge exciton binding energy and the large dipole moments of Wannier-like excitons enable us to induce the dipole trap of the order of meV depth and μm width. This Letter opens a new way to control light-exciton interacting systems based on newly developed numerically robust ab initio calculations.
近期，针对二维材料中的激子展开了广泛研究，因其在新型电子和光学器件方面具有潜在用途。特别是，对激子量子自由度的精密操控技术备受需求。在本信函中，我们基于第一性原理计算，提出了一种在二维宽禁带半导体石墨烷中形成激子光学偶极阱的技术。我们开发了一种第一性原理方法来评估激子态之间的跃迁偶极矩，并将其与密度泛函理论及GW + BSE计算相结合。我们揭示出，在石墨烷中，巨大的激子束缚能以及类万尼尔激子的大偶极矩使我们能够诱导出深度为meV量级、宽度为μm量级的偶极阱。本信函基于新开发的数值稳健的从头计算，开辟了一种控制光 - 激子相互作用系统的新途径。
