Yksifotonilähteet kaksiulotteisissa siirtymämetalli dikalkogeeneissä

Le résumé fourni par la source

The emergence of quantum photonics has ignited a large amount of interest in singlephoton sources (SPS). These sources are required in many quantum technology applications, such as various quantum computing protocols and quantum key distribution (QKD). Recently, SPSs have been realized in two-dimensional (2D) transition metal dichalcogenides (TMDC). The characteristic crystal structure of these materials enables unique electronic and optical properties, which are beneficial in SPS applications. However, the SPSs in these materials are usually randomly located as they originate from crystalline defects, which complicates further investigation. Nevertheless, it has been recently discovered that by applying strain, one can induce SPSs in these materials, which allows spatial localization of the sources. This thesis demonstrates the possibility of achieving single-photon emission of strained 2D TMDCs. In order to create SPSs, mechanically exfoliated tungsten diselenide (WSe2) and molybdenum ditelluride (MoTe2) samples were transferred on top of the array causing them to be strained at the pillar locations. The samples were then characterized by measuring their photoluminescence (PL) spectra and time-resolved PL decay at low temperature. The results indicate that single-photon emission was acquired from the WSe2 sample around the pillar area. However, no such emission was noticed with the MoTe2 sample. This might be due to its relatively large thickness. Additionally, the sample might have reacted with oxygen and water in the air, due to its instability. Both of these factors reduce the PL yield of the material, and thus further experiments are required to fully confirm the possibility of obtaining single-photon emission from MoTe2. The results for the WSe2 sample show that it is possible to fabricate spatially localized SPSs by applying strain. This allows a more extensive further investigation involving concepts such as spin–valley coupling and integrated quantum photonics.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.