| Full text | |
| Author(s): |
Qu, Fanyao
[1]
;
Braganca, Helena
[2, 1]
;
Vasconcelos, Railson
[1]
;
Liu, Fujun
[1]
;
Xie, S-J
[3]
;
Zeng, Hao
[4]
Total Authors: 6
|
| Affiliation: | [1] Univ Brasilia, Inst Fis, BR-70919970 Brasilia, DF - Brazil
[2] Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, SP - Brazil
[3] Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong - Peoples R China
[4] Univ Buffalo State Univ New York, Dept Phys, Buffalo, NY 14260 - USA
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | 2D MATERIALS; v. 6, n. 4 OCT 2019. |
| Web of Science Citations: | 1 |
| Abstract | |
We developed a comprehensive theoretical framework focusing on many-body effects of exciton species in monolayer WS2, including bright and dark excitons, and intra- and inter-valley biexcitons, to investigate valley dynamics in monolayer WS2 subjected to a tilted magnetic field B. In particular, the evolution of the exciton population densities and the many-body particle scatterings are considered to calculate the valley polarization (VP) as a function of the magnetic field. We found valley splittings for the dark exciton and biexciton energy levels that are larger than those of bright excitons, of -0.23 meV T-1. For example, -0.46 meV T-1 for dark excitons and -0.69 meV T-1 for bright-dark intra-valley biexcitons. Furthermore, inter-valley bright-dark excitons have an opposite valley energy splittings of +0.23 meV T-1. For the samples pumped by linearly polarized light, VP exhibits distinct magnetic field dependence for different types of many-body particle states. Among them, the VP of the intra-valley bright-dark biexcitons increases with increasing magnetic field and reaches nearly 50% at B = 65 T. The brightened dark exciton, on the other hand, exhibits vanishing VP, indicating long valley relaxation time. Remarkably, the inter-valley bright-dark biexciton shows unconventional behavior with an inverted VP. The opposite VP for intra- and inter-valley bright-dark biexcitons, coupled with their large valley splitting and long valley lifetime may facilitate their coherent manipulation for quantum computing. (AU) | |
| FAPESP's process: | 17/23668-8 - Many-body effects on Valley qubits and on the magneto-optical properties of transition metal dichalcogenide monolayers |
| Grantee: | Helena de Souza Bragança Rocha |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |