There is a growing interest in the study of polaritonic systems, mixed states of photons and excitons, for both, the observation of quantum macroscopic phenomena, and the realisation of all-optical devices that could offer... [ view full abstract ]
There is a growing interest in the study of polaritonic systems, mixed states of photons and excitons, for both, the observation of quantum macroscopic phenomena, and the realisation of all-optical devices that could offer limitless advantages in terms of energy consumption, dissipation-less operation and high clock frequencies1. More recently, entangling one photon with one polariton, it has even been shown that these particles can also be ideal carriers of quantum information2.
Here we show several macroscopic quantum phenomena that can be observed in polariton condensates, both at low temperature, in inorganic semiconductor microcavities–for which the very long lifetime allows the formation of the BKT phase3, typical of equilibrium systems–and in organic based polaritons, where phenomena like superfluidity can be observed up to room temperature4. We also speculate on the possibility of using hybrid semiconductors with reduced dimensionality to achieve the regime of highly interacting polaritons. These materials include monocrystalline two-dimensional perovskites and transition metal dichalcogenides that have demonstrated nonlinear responses similar to those of low temperature inorganic semiconductors. Such results move in the direction of using polaritons as ultrafast and efficient electro-optical converters, optical switches and transistors.
References
1.Sanvitto, D. & Kena-Cohen, S. The road towards polaritonic devices. Nat. Mater. 15, 1061–1073 (2016).
2.Cuevas, Á. et al. First observation of the quantized exciton-polariton field and effect of interactions on a single polariton. Sci. Adv. 4, eaao6814 (2018).
3.Caputo, D. et al. Topological order and thermal equilibrium in polariton condensates. Nat. Mater. 17, 145–151 (2018).
4.Lerario, G. et al. Room-temperature superfluidity in a polariton condensate. Nat Phys 13, 837 (2017).
