Toward Room Temperature One-Dimensional Quantum Fluid in the Solid State: Exciton Polaritons in Zinc Oxide Microwires

Abstract

Exciton-polaritons in semiconductor nanostructures constitute a model system of quantum fluid of ultra light Bose excitations in a driven-dissipative situation. Owing to recent progresses in the domain of nanofabrications, polaritons environment may now be tuned at will in terms of external potential and dimensionality. In this chapter we present a nanostructure of particular interest to generate and manipulate one dimensional polaritons with unusual properties: ZnO microwires. Within such a structure we show that polaritons are stable at room temperature and have the property of being strongly decoupled from the lattice thermal vibrations, therefore naturally protected from thermal decoherence. We also find that at cryogenic temperature, the 1D superfluid phase is surprising as polaritons are much heavier than usual and quasi purely excitonic in nature. At room temperature, another polariton superfluid phase is also observed, and several experimental facts indicate that the strong coupling is well preserved in spite of a much larger critical density.