Exciton-polaritons with 2D materials, from cryogenic to ambient conditions

Dr. Carlos Anton-Solanas, Oldenburg Carl von Ossietzky University (Germany)

09/12/2021, 12am MSK / 10 am CET

Abstract

Atomically thin crystals of transition metal dichalcogenides (TMDCs) have emerged as a new platform to study tightly bound excitons and many-body excitations in ultimately thin materials. Their giant dipole coupling to light makes them prime materials for (nano-)photonic and electronic devices, and for fundamental research on cavity quantum electrodynamics. Additionally, TMDC excitons can emit at room temperature and they offer unique, tailorable interactions based on van-der-Waals engineering.

The strong coupling between excitons and confined photons yields the formation of exciton-polaritons; these are solid-state quasiparticles with properties linked to matter (Coulomb interactions, magnetic response) and light (extended spatial and temporal coherence). The bosonic character of exciton-polaritons enables their capability to condense into a macroscopic coherent state [1], similar to the laser emission, with additional features such as controllable nonlinear interactions.

In this talk, I will firstly discuss our recent results on the condensation of TMDC exciton-polaritons at cryogenic temperatures [2], created in a sample embedding a monolayer of MoSe2 in a hybrid optical microcavity composed by AlGaAs mirrors and a dielectric top mirror. Secondly, in a different sample composed by a monolayer of WSe2 embedded in a fully dielectric mirror, I will show recent results on condensation signatures of room-temperature TMDC exciton-polaritons (extended first order coherence) [3].

Our future experiments will explore open-cavity configurations containing optical lattices (see recent related work [4]) coupled to TMDC interlayer excitons [5]. We believe that this platform offers a powerful approach to study complex systems, such as the Bose-Hubbard model.

[1] J. Kasprzak, et al. Nature 443, 409 (2006).

[2] C. Anton-Solanas, et al. Nature Materials 20, 1233 (2021).

[3] H. Shan, et al. Nature Communications 12, 6406 (2021).

[4] L. Lackner, Nat Commun 12, 4933 (2021).

[5] Michl, arXiv:2105.09948 [cond-mat] (2021).

About the speaker

Carlos did is PhD in the group of Prof. Viña (Univ. Autonoma of Madrid, 2015, Spain), on the properties of exciton-polariton condensates in III-V microcavities. During his 1st postdoc (CNRS, 2015-2019, France), he worked on solid-state quantum optics in the group of Prof. Senellart, using quantum dots coupled to micropillar cavities. During his 2nd postdoc (Univ. Würzburg, 2019-2020, Germany) he worked on excitons and exciton-polaritons in atomically thin crystals of transition metal dichalcogenides. From July 2020, Carlos joined Prof. Christian Schneider to create an experimental research group in the Institute of Physics of the Univ. of Oldenburg, where he is doing his Habilitation on “Quantum Photonics with Quantum Materials”.


Date & Location

The event will be taking place on the 09th of December 2021 at 12 am MSK time (10 am CET).

Access details: Zoom (Meeting ID: 962 4930 8286 / Passcode: 457552)

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