Coupled exciton-trion spin dynamics in a MoSe2 monolayer. (3rd September 2018)

• Record Type: Journal Article
• Authors: Anghel, S; Passmann, F; Ruppert, C; Bristow, A D; Betz, M
• Is Part Of: 2D materials. Volume 5:Number 4(2018)
• Publication Date: 2018-09-03
• Subjects: MoSe2 monolayer -- Kerr effect -- exciton-trion coupling -- spin coherence time -- ultrashort nonlinear spectroscopy -- time-resolved confocal microscopy; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aadbd8
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Understanding and controlling the spin degree of freedom in two-dimensional transition metal dichalcogenides offers the potential for designing functional quantum materials. This work investigates the dynamics of photo- and resident carrier spins in an encapsulated MoSe2 monolayer using non-degenerate time-resolved Kerr-rotation microscopy. The lightly doped monolayer exhibits clear exciton and trion resonances with spin-polarizations that are characterized by a fast (~20 ps) decay attributed to photocarrier relaxation and recombination, followed by a slow (~690 ps) decay associated with resident carrier depolarization. Dual-frequency Kerr-rotation spectra directly reveal exciton-trion coupling on ultrashort timescales and within the spin coherence time of the system. Moreover, the distribution of the exciton-trion coupling features exposes inhomogeneous broadening likely arising from different domains within the excitation spot.