Controlled coherent-coupling and dynamics of exciton complexes in a MoSe2 monolayer

Quantifying and controlling the coherent dynamics and couplings of optically active excitations in solids is of paramount importance in fundamental research in condensed matter optics and for their prospective optoelectronic applications in quantum technologies. Here, we perform ultrafast coherent nonlinear spectroscopy of a charge-tunable MoSe2 monolayer. The experiments show that the homogeneous and inhomogeneous line width and the population decay of exciton complexes hosted by this material can be directly tuned by an applied gate bias, which governs the Fermi level and therefore the free carrier density. By performing two-dimensional spectroscopy, we also show that the same bias-tuning approach permits us to control the coherent coupling strength between charged and neutral exciton complexes.

Automated summary

In this study, we performed ultrafast coherent nonlinear spectroscopy of a charge-tunable MoSe2 monolayer. The experiments showed that the properties of exciton complexes, such as line width and population decay, can be directly tuned by an applied gate bias. Furthermore, we demonstrated that this bias-tuning approach can also control the coherent coupling strength between charged and neutral exciton complexes.