Programme

P.35 -- Posters, VCTP-50

Date: Tuesday, 5 August 2025

Time: 08:30 - 10:00

REGULATED PERTURBATION THEORY FOR ANISOTROPIC 2D EXCITON AND A VARIABLE SEPARATION PROCEDURE FOR COMPLICATED DOUBLE INTEGRALS

Le Do Dang Khoa, Le Hoang Viet, Le Van Hoang

Ho Chi Minh City University of Education

After the success of graphene, a series of new two-dimensional materials were born with many important applications in optoelectronics. Exciton plays an important role in the research and development of two-dimensional semiconductor materials and has been widely studied over the years. In this paper, we develop and improving the regulated perturbation theory for anisotropic exciton base on an algebraic method approach to the calculation of energy spectrum and wavefunction of exciton in black phosphorus monolayer which has an anisotropic structure. The regulated perturbation theory is the theory of combining the perturbation method and Feranchuk-Komarov operator method. These methods include the scaling space, Levi-Civita transformation, the algebraic calculation using the annihilation and creation operators, and introduction to the free parameter which have a role in optimize the convergence rate. At the same time, a computational procedure is proposed for evaluating a specific form of double integral that characterizes the anisotropic structure of black phosphorus (BP). This integral exhibits a highly complicated form, and the proposed method significantly reduces the computational cost—by up to hundreds of thousands of times. Our results are highly accurate up to six decimal places for both energy spectrum and wavefunction and well agreement with the experiment. These results are an important step, promoting research on excitons in anisotropic monolayers by algebraic and analytical methods later.

Presenter: Le Do Dang Khoa