Intense anomalous high harmonics in graphene quantum dots caused by disorder or vacancies

التفاصيل البيبلوغرافية
العنوان: Intense anomalous high harmonics in graphene quantum dots caused by disorder or vacancies
المؤلفون: Avetissian, H. K., Musayelyan, G. A., Mkrtchian, G. F.
سنة النشر: 2023
المجموعة: Condensed Matter
Physics (Other)
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Optics
الوصف: This article aims to study the linear and nonlinear optical response of inversion symmetric graphene quantum dots (GQDs) in the presence of on-site disorder or vacancies. The presence of disorder or vacancy breaks the special inversion symmetry leading to the emergence of intense Hall-type anomalous harmonics. This phenomenon is attributed to the intrinsic time-reversal symmetry-breaking in quantum dots with a pseudo-relativistic Hamiltonian, even in the absence of an external magnetic field. We demonstrate that the effects induced by disorder or vacancy have a distinct impact on the optical response of GQDs. In the linear response, we observe significant Hall conductivity. In the presence of an intense laser field, we observe the radiation of strong anomalous odd and even-order harmonics already for relatively small levels of disorder or mono-vacancy. The both disorder and vacancy lift the degeneracy of states, thereby creating new channels for interband transitions and enhancing the emission of near-cutoff high-harmonic signals.
Comment: 9 pages, 8 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2310.16596
رقم الأكسشن: edsarx.2310.16596
قاعدة البيانات: arXiv