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arXiv · 1506.03905

Optical investigation of monolayer and bulk tungsten diselenide (WSe$_{2}$) in high magnetic fields

A. A. Mitioglu·P. Plochocka·Á. Granados del Aguila·P. C. M. Christianen·G. Deligeorgis·S. Anghel·L. Kulyuk·D. K. Maude
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Abstract

Optical spectroscopy in high magnetic fields $B\leq65$ T is used to reveal the very different nature of carriers in monolayer and bulk transition metal dichalcogenides. In monolayer WSe$_{2}$, the exciton emission shifts linearly with the magnetic field and exhibits a splitting which originates from the magnetic field induced valley splitting. The monolayer data can be described using a single particle picture with a Dirac-like Hamiltonian for massive Dirac fermions, with an additional term to phenomenologically include the valley splitting. In contrast, in bulk WSe$_{2}$ where the inversion symmetry is restored, transmission measurements show a distinctly excitonic behavior with absorption to the 1s and 2s states. Magnetic field induces a spin splitting together with a small diamagnetic shift and cyclotron like behavior at high fields, which is best described within the hydrogen model.

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A. A. Mitioglu, P. Plochocka, Á. Granados del Aguila, P. C. M. Christianen, G. Deligeorgis, S. Anghel, L. Kulyuk, D. K. Maude. 2015-06-15. Optical investigation of monolayer and bulk tungsten diselenide (WSe$_{2}$) in high magnetic fields. https://doi.org/10.1021/acs.nanolett.5b00626

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