tailieunhanh - Linear and nonlinear magneto optical absorption coefficients and refractive index changes in WSe monolayer

This work studies the linear, the third-order nonlinear, and the total optical absorption coefficients (OACs) and the refractive index changes (RICs) caused by both intra-and inter-band transitions in the WSe2 monolayer. | VNU Journal of Science Mathematics Physics Vol. 37 No. 4 2021 59-67 Original Article Linear and Nonlinear Magneto-optical Absorption Coefficients and Refractive Index Changes in Wse2 Monolayer Luong Van Tung1 Nguyen Quang Bau2 Tran Ngoc Bich3 4 Pham Tuan Vinh5 Huynh Vinh Phuc5 1 Sai Gon University 273 An Duong Vuong Ho Chi Minh City Vietnam 2 VNU University of Science 334 Thanh Xuan Nguyen Trai Hanoi Vietnam 3 University of Education Hue University 32 Le Loi Hue City Vietnam 4 Quang Binh University 312 Ly Thuong Kiet Dong Hoi Quang Binh Vietnam 5 Dong Thap University 783 Pham Huu Lau Dong Thap Vietnam Received 02 February 2021 Revised 21 April 2021 Accepted 21 April 2021 Abstract This work studies the linear the third-order nonlinear and the total optical absorption coefficients OACs and the refractive index changes RICs caused by both intra- and inter-band transitions in the WSe2 monolayer. The expression for the OACs and RICs in the presence of a magnetic field as well as the Zeeman and electric fields are found by using the compact density matrix approach. The results show that the spin states strongly affect the OACs and RICs which display the violet-shift behavior with the increase of the magnetic field. The Zeeman fields do not affect the peak positions but slightly reduce peak intensities. The OACs and RICs due to intra-band transition display only one peak in the THz range while the inter-band spectra show a series of peaks in the near-infrared optical range making monolayer WSe2 be a promising candidate for novel optoelectronic applications. Keywords WSe2 monolayer optical absorption coefficients refractive index changes magnetic field. 1. Introduction In recent years studies on the transition metal dichalcogenides TMDCs have been developed rapidly due to their fascinating electronic and optical properties including the large natural band gap and _ Corresponding author. E-mail address hvphuc@ https 2588-1124 59 60 .