Bosonic condensation of exciton–polaritons in an atomically thin crystal

Antón-Solanas, Carlos; Waldherr, Maximilian; Klaas, Martin; Suchomel, Holger; Harder, Tristan H.; Cai, Hui; Sedov, Evgeny; Klembt, Sebastian; Kavokin, Alexey; Tongay, Sefaattin; Watanabe, Kenji; Taniguchi, Takashi; Höfling, Sven; Schneider, Christian

doi:10.1038/s41563-021-01000-8

Cited by 77 publications

(88 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the presence of an externally applied magnetic field, the valley degeneracy is lifted via the valley-Zeeman effect 31 – 35 resulting in two circularly polarized optical transitions. Consequently, exciton-polaritons formed by valley excitons display an analogous Zeeman energy-splitting under a magnetic field 22 , which clearly distinguishes them from cavity photons, and which provides a unique control knob in Valley Polaritonics 36 .…”

Section: Resultsmentioning

confidence: 99%

“…Our work tackles the crucial question, whether exciton-polaritons, which are created in an atomically thin crystal sheet of WSe 2 18 – 21 coupled to an optical microcavity, can emit coherent light at room temperature. Indeed, utilizing atomically thin transition metal dichalcogenides in polaritonic light sources and condensates 22 can pave the way towards a multiplicity of interesting applications and experiments. The locking of spin and valley in those materials profoundly changes optical selection rules, and the resulting chirality can be harnessed in topological nanophotonic applications 23 , 24 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap

et al. 2021

Self Cite

View full text Add to dashboard Cite

The emergence of spatial and temporal coherence of light emitted from solid-state systems is a fundamental phenomenon intrinsically aligned with the control of light-matter coupling. It is canonical for laser oscillation, emerges in the superradiance of collective emitters, and has been investigated in bosonic condensates of thermalized light, as well as exciton-polaritons. Our room temperature experiments show the strong light-matter coupling between microcavity photons and excitons in atomically thin WSe2. We evidence the density-dependent expansion of spatial and temporal coherence of the emitted light from the spatially confined system ground-state, which is accompanied by a threshold-like response of the emitted light intensity. Additionally, valley-physics is manifested in the presence of an external magnetic field, which allows us to manipulate K and K’ polaritons via the valley-Zeeman-effect. Our findings validate the potential of atomically thin crystals as versatile components of coherent light-sources, and in valleytronic applications at room temperature.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…As a direct consequence, polaritons as dual light-matter quasi-particles are formed and considerably change the bandstructure, optics, dynamics and transport properties of semiconductors. A promising class of materials for the strong-coupling regime are monolayers of transition metal dichalcogenides (TMDs) [6][7][8][9][10]. They exhibit a large oscillator strength and exciton binding energies in the range of a few hundreds of meV governing the optoelectronic properties of these materials [11][12][13][14][15] and have been hence widely investigated in planar microcavities [6,9,16].…”

Section: Introductionmentioning

confidence: 99%

Microscopic modelling of exciton-polariton diffusion coefficients in atomically thin semiconductors

Ferreira¹,

Rosati²,

Malić³

2022

Preprint

View full text Add to dashboard Cite

In the strong light-matter coupling regime realized e.g. by integrating semiconductors into optical microcavities, polaritons as new hybrid light-matter quasi-particles are formed. The corresponding change in the dispersion relation has a large impact on optics, dynamics and transport behaviour of semiconductors. In this work, we investigate the strong-coupling regime in hBN-encapsulated MoSe2 monolayers focusing on exciton-polariton diffusion. Applying a microscopic approach based on the exciton density matrix formalism combined with the Hopfield approach, we predict a drastic increase of the diffusion coefficients by two to three orders of magnitude in the strong coupling regime. We explain this behaviour by the much larger polariton group velocity and suppressed polaritonphonon scattering channels with respect to the case of bare excitons. Our study contributes to a better microscopic understanding of polariton diffusion in atomically thin semiconductors.

show abstract

“…In contrast to conventional lasers that need to be driven to an electronic population inversion, polariton lasers emit coherent light through enhanced bosonic scattering into a common state [7,13,14]. Given the light mass polaritons inherit from their photonic part, this effect, which is closely related to Bose-Einstein condensation [15], already happens at moderately cryogenic temperatures in gallium arsenide, and even at room temperature for organic polaritons and atomically thin crystals with their much tighter bound excitons [16][17][18][19]. The threshold for the onset of enhanced coherence is much lower without the need for a population inversion, and the scattering into a common state enables measuring the particle-density dependent blueshift.…”

Section: Introductionmentioning

confidence: 99%

Polariton Lasing in Micropillars With One Micrometer Diameter and Position-Dependent Spectroscopy of Polaritonic Molecules

Czopak¹,

Prilmüller²,

Schneider³

et al. 2021

Preprint

View full text Add to dashboard Cite

Microcavity polaritons are bosonic light-matter particles that can emit coherent radiation without electronic population inversion via bosonic scattering. This phenomenon, known as polariton lasing, strongly depends on the polaritons' confinement. Shrinking the polaritons' mode volume increases the interactions mediated by their excitonic part, and thereby the density-dependent blueshift of the polariton to a higher energy is enhanced. Previously, polariton lasing has been demonstrated in micropillars with diameters larger than three microns, in grating based cavities, fiber cavities and photonic crystal cavities. Here we show polariton lasing in a micropillar with one micron diameter operating in a single transverse mode that can be optimally coupled to a singlemode fiber. We geometrically decouple the excitation with an angle from the collection. From the number of collected photons we calculate the number of polaritons and observe a blueshift large enough to qualify our device for novel schemes of quantum light generation such as the unconventional photon blockade. To that end, we also apply angled excitation to polaritonic molecules and show site-selective excitation and collection of modes with various symmetries.

show abstract

Bosonic condensation of exciton–polaritons in an atomically thin crystal

Cited by 77 publications

References 39 publications

Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap

Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap

Microscopic modelling of exciton-polariton diffusion coefficients in atomically thin semiconductors

Polariton Lasing in Micropillars With One Micrometer Diameter and Position-Dependent Spectroscopy of Polaritonic Molecules

Contact Info

Product

Resources

About