Bose-Einstein condensation of exciton polariton in perovskites semiconductors
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Bose-Einstein condensation of exciton polariton in perovskites semiconductors Xinglin WEN1, Qihua XIONG (✉)2 1 School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China 2 Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
© Higher Education Press 2020
Polariton-hybridization of light-matter oscillations can emerge from various quasiparticles, such as phonon, plasmon, exciton and magnon. Particularly, exciton polaritons are bosonic quasiparticles with half-light, halfmatter nature, which are originated from strong coupling between excitons and microcavity photons. The half-light nature results in extremely small effective mass, making it feasible to achieve high temperature even room-temperature Bose-Einstein condensation (BEC). Meanwhile, the half-matter nature leads to strong nonlinear interaction, which is missing between photons and can promote the polaritons relaxation to ground state and give rise to low threshold polariton lasing, compared to photonic lasing. The exciton polaritons are of great importance in applications of quantum simulation, topological quantum optics, ultrafast optical switch and low threshold lasers. Usually, exciton polaritons are realized by coupling the semiconductor to an optical cavity to achieve strong lightmatter interaction. The excitonic fraction of polaritons can be tuned by changing the detuning, namely, the energy difference between exciton and cavity resonance at kk ¼ 0. The coupling strength is reflected by the Rabi splitting energy. Cavity exciton polariton was firstly demonstrated in GaAs quantum wells (QWs) sandwiched by two distributed Bragg reflectors (DBRs) in 1992 [1]. Later on, the polariton condensation was observed in CdTe QWs at 5 K in 2006 [2]. The Wannier-Mott exciton in GaAs or CdTe has small exciton binding energy, which renders that polariton condensation must operate at cryogenic temperature. In contrast, the large exciton binding energy in ZnO [3] or GaN [4] can sustain room temperature Received August 20, 2020 E-mail: [email protected]
polariton. However, for the inorganic materials, it demands sophisticated epitaxial techniques such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) to grow both the planar cavity and semiconductor film, which is constrained by the defects, strain and the lattice mismatch problems. On the other hand, the binding energy of Frankel exciton in organic materials is large enough to support room temperature polariton. The organic materials also hold the advantages of facile synthesis and large range of species. Nonetheless, the Frankel exiciton nature renders it suffers from small Coulomb interaction and thus weak polariton-polariton interaction, leading to much smaller nonlinearity and higher polariton lasing threshold compared with inorganic materials. To this end, it is desired to have ma
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