VALLEY SPLITTING AND MAGNON-EXCITON COUPLING IN TRANSITION METAL DICHALCOGENIDES USING SEMICONDUCTING ANTIFERROMAGNETS
Date
2023-05
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
Valleytronics presents an innovative approach to the storage and manipulation
of binary and quantum information. The availability of 2D materials has opened up
exciting possibilities for exploring Valleytronics in transition metal dichalcogenides
(TMDCs), owing to their valley-contrasting orbital magnetic moments and optical
selection rules. While the selective control of K and K' valleys in TMDCs can be
achieved by lifting the valley degeneracy using an external magnetic field, this
approach has proven impractical due to the weak Zeeman splitting. Fortunately, the
magnetic proximity effect obtained by interfacing a TMDC with a ferromagnet offers
a solution that lifts the valley degeneracy even further. However, the realization of
valley splitting via the magnetic proximity effect induced by a semiconducting
antiferromagnet (AFM) has remained elusive. In addition, simultaneously establishing
magnon-exciton coupling in a heterostructure of an AFM and TMDC while breaking
the valley degeneracy in the TMDC would represent significant progress in the field of
Valleytronics. This thesis sets forth a path forward toward achieving this goal using
the semiconducting AFM CrPS4 and the TMDC WSe2, including the necessary
fabrication procedure.