Bose condensation of upper-branch exciton-polaritons in a transferrable microcavity

Abstract

Exciton-polaritons are composite bosonic quasiparticles arising from the strong coupling of excitonic transitions and optical modes. Exciton-polaritons have triggered wide exploration in the past decades not only due to their rich quantum phenomena such as superfluidity, superconductivity and quantized vortices but also due to their potential applications for unconventional coherent light sources and all-optical control elements. Here, we report the observation of Bose-Einstein condensation of the upper polariton branch in a transferrable WS${}_2$ monolayer microcavity. Near the condensation threshold, we observe a nonlinear increase in upper polariton intensity. This sharp increase in intensity is accompanied by a decrease of the linewidth and an increase of the upper polariton temporal coherence, all of which are hallmarks of Bose-Einstein condensation. By simulating the quantum Boltzmann equation, we show that the upper polariton condensation only occurs for a particular range of particle density. We can attribute the creation of Bose condensation of the upper polariton to the following requirements: 1) the upper polariton is more excitonic than the lower one; 2) there is relatively more pumping in the upper branch; and 3) the conversion time from the upper to the lower polariton branch is long compared to the lifetime of the upper polaritons.

References in corpus (24)

• Atomically thin MoS2: A new direct-gap semiconductor
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• Excitons in atomically thin transition metal dichalcogenides
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• Tightly bound excitons in monolayer WSe2
• Strong light-matter coupling in two-dimensional atomic crystals
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Exciton photon strong-coupling regime for a single quantum dot in a microcavity
• All-optical polariton transistor
• Room Temperature Polariton Lasing in All-Inorganic Perovskites
• Realizing the $XY$ Hamiltonian in polariton simulators
• Optical circuits based on Polariton Neurons in Semiconductor Microcavities
• Room temperature Tamm-Plasmon Exciton-Polaritons with a WSe2 monolayer
• Controlling the Spontaneous Emission Rate of Monolayer MoS${}_2$ in a Photonic Crystal Nanocavity
• Van der Waals Heterostructure Polaritons with moiré-Induced Nonlinearity
• Bose-Einstein Condensation of Long-Lifetime Polaritons in Thermal Equilibrium
• Control of Two-Dimensional Excitonic Light Emission via Photonic Crystal
• Exciton-exciton interaction in transition-metal dichalcogenide monolayers
• Ultralow Threshold Polariton Condensate in a Monolayer Semiconductor Microcavity at Room Temperature
• Bosonic condensation of exciton-polaritons in an atomically thin crystal
• Polaritonic neuromorphic computing outperforms linear classifiers
• Non-Hermitian phase transition from a polariton Bose-Einstein condensate to a photon laser
• Stimulated emission of terahertz radiation by semiconductor microcavities
• Micro- Mechanical assembly of high-quality Fabry-Perot microcavities for the integration with two-dimensional materials