Room Temperature Terahertz Electroabsorption Modulation by Excitons in Monolayer Transition Metal Dichalcogenides
Author(s)Shi, Jiaojian; Baldini, Edoardo; Latini, Simone; Sato, Shunsuke A; Zhang, Yaqing; Pein, Brandt C; Shen, Pin-Chun; Kong, Jing; Rubio, Angel; Gedik, Nuh; Nelson, Keith A; ... Show more Show less
MetadataShow full item record
Copyright © 2020 American Chemical Society. The interaction between off-resonant laser pulses and excitons in monolayer transition metal dichalcogenides is attracting increasing interest as a route for the valley-selective coherent control of the exciton properties. Here, we extend the classification of the known off-resonant phenomena by unveiling the impact of a strong THz field on the excitonic resonances of monolayer MoS2. We observe that the THz pump pulse causes a selective modification of the coherence lifetime of the excitons, while keeping their oscillator strength and peak energy unchanged. We rationalize these results theoretically by invoking a hitherto unobserved manifestation of the Franz-Keldysh effect on an exciton resonance. As the modulation depth of the optical absorption reaches values as large as 0.05 dB/nm at room temperature, our findings open the way to the use of semiconducting transition metal dichalcogenides as compact and efficient platforms for high-speed electroabsorption devices.
American Chemical Society (ACS)