Coherent quantum dynamics of excitons in monolayer transition metal dichalcogenides
Paper i proceeding, 2016

Transition metal dichalcogenides (TMDs) have garnered considerable interest in recent years owing to their layer thickness-dependent optoelectronic properties. In monolayer TMDs, the large carrier effective masses, strong quantum confinement, and reduced dielectric screening lead to pronounced exciton resonances with remarkably large binding energies and coupled spin and valley degrees of freedom (valley excitons). Coherent control of valley excitons for atomically thin optoelectronics and valleytronics requires understanding and quantifying sources of exciton decoherence. In this work, we reveal how exciton-exciton and exciton-phonon scattering influence the coherent quantum dynamics of valley excitons in monolayer TMDs, specifically tungsten diselenide (WSe2), using two-dimensional coherent spectroscopy. Excitation-density and temperature dependent measurements of the homogeneous linewidth (inversely proportional to the optical coherence time) reveal that exciton-exciton and exciton-phonon interactions are significantly stronger compared to quasi-2D quantum wells and 3D bulk materials. The residual homogeneous linewidth extrapolated to zero excitation density and temperature is 1:6 meV (equivalent to a coherence time of 0.4 ps), which is limited only by the population recombination lifetime in this sample. (c) (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only







Multi-Dimensional Coherent Spectroscopy


mono layer

Homogeneous Linewidth

valley polarization

Transition Metal Dichalcogenides




G. Moody

National Institute of Standards and Technology

The University of Texas at Austin

K. Hao

The University of Texas at Austin

C. K. Dass

The University of Texas at Austin

A. Singh

The University of Texas at Austin

L. X. Xu

The University of Texas at Austin

K. Tran

The University of Texas at Austin

C. H. Chen

Feng Chia University

M. Y. Li

King Abdullah University of Science and Technology (KAUST)

L. J. Li

King Abdullah University of Science and Technology (KAUST)

G. Clark

University of Washington

Gunnar Berghäuser

Technische Universität Berlin

Ermin Malic

Chalmers, Fysik, Kondenserade materiens teori

A. Knorr

Technische Universität Berlin

X. D. Xu

University of Washington

X. Q. Li

The University of Texas at Austin

Proceedings of SPIE - The International Society for Optical Engineering

0277786X (ISSN) 1996756X (eISSN)

Vol. 9746 97461T


Atom- och molekylfysik och optik

Elektroteknik och elektronik





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