Regensburg 2016 – scientific programme
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DS: Fachverband Dünne Schichten
DS 6: Graphene: Theory
(Joint session of DS, DY, HL, MA, O and TT organized by HL)
DS 6.7: Talk
Monday, March 7, 2016, 11:30–11:45, H17
Ab initio studies of excitations in monolayer black phosphorus — •Tobias Frank1, Marcin Kurpas1, Martin Gmitra1, Rene Derian2, Ivan Stich2, and Jaroslav Fabian1 — 1Universität Regensburg, Regensburg, Germany — 2Slovak Academy of Sciences, Bratislava, Slovakia
Monolayer black phosphorus, or phosphorene, represents an ideal system to study many-body electron-electron and electron-hole interactions due to its strong anisotropy driven 1d electronic nature. In particular, the size of the fundamental band gap value and excitonic binding energies remain unresolved given the different gap values of 1.6 to 2.4 eV [1] obtained by many-body GW calculations. We present our contribution to this issue studying excitations in phosphorene employing quantum monte carlo (QMC) calculations. We show the evolution of finite size effects of the fundamental and optical gap, with respect to relatively large supercell sizes in the theoretical framework of diffusion monte carlo (DMC) explicitly including electronic correlations. Our studies point to a significant influence of electron correlation on the fundamental gap as well as to a strong anisotropic nature of the excitonic state. Furthermore we address the question of a multiconfigurational ground state in monolayer black phosphorus. This work is supported by the DFG GRK 1570, SFB 689, and European Union Seventh Framework Programme under Grant Agreement No. 604391 Graphene Flagship.
[1] A. N. Rudenko, Shengjun Yuan, and M. I. Katsnelson, Phys. Rev. B 92 085419 (2015)