Excitonic Properties of Localized Emitters from Monolayer WSe2 an WSe2/MoSe2 Heterobilayer
- PC Department Online Seminar
- Date: Feb 23, 2021
- Time: 04:00 PM (Local Time Germany)
- Speaker: Dr. Xiu Lu
- Tulane University, New Orleans, USA
In this talk, I will focus on discussing the excitonic properties of
these localized emitters from atomically thin TMDC-based structure. I
will start by presenting that a localized exciton in monolayer WSe2 can
carry a net charge and a resident spin. Subsequently, I will show our
experimental demonstration of optical initialization from the singly,
positively charged localized exciton2. Next, I will present our
experimental result obtained from a WSe2/MoSe2 heterobilayer. We
observed that the localized exciton displays a single permanent dipole,
which enables energy tunability by the application of out-of-plane
electric field. In addition, the repulsive dipole-dipole interaction
causes the second excitation to be blue-shifted, which is distinct from
the
conventional “biexciton” 3,4.
1. M. Atatüre et al. Material platforms for spin-based photonic quantum technologies. Nature Reviews Materials 3, 38-51 (2018).
2.
X. Lu, X. Chen, S. Dubey et al. Optical initialization of a single
spin-valley in charged WSe2 quantum dots. Nature Nanotechnology 14,
426-431 (2019).
3. W. Li, X. Lu et
al. Dipolar interactions between field-tuneable, localized emitters in
van der Waals heterostructures. Nature Materials 19, 624-629 (2020).
4.
M. Kremser et al. Discrete interactions between a few interlayer
excitons trapped at a MoSe2–WSe2 heterointerface. npj 2D Materials and
Applications 4, 8 (2020).
5. X.
Chen, X. Lu, S. Dubey et al. Entanglement of single-photons and chiral
phonons in atomically thin WSe2. Nature Physics 15, 221-227 (2019).
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