Two-dimensional spectroscopy of atomically thin 2D materials

Abstract Two-dimensional spectroscopy experiments on atomically thin semiconductors, specifically transition metal dichalcogenides, are presented in this chapter. An introduction to 2D materials is given, followed by experiments measuring the homogeneous and inhomogeneous linewidth in 2D materials. Signature of exciton valley coherence and exciton-trion coherent coupling are revealed as unique spectral features in the spectra, which sheds light on the valley dephasing and relaxation processes in these materials.