High-resolution coherent probe spectroscopy of a polariton quantum fluid

Abstract

Characterising elementary excitations in quantum fluids is essential to study collective effects within. We present an original angle-resolved coherent probe spectroscopy technique to study the dispersion of these excitation modes in a fluid of polaritons under resonant pumping. Thanks to the unprecedented spectral and spatial resolution, we observe directly the low-energy phononic behaviour and detect the negative-energy modes, i.e. the \textit{ghost branch}, of the dispersion relation. In addition, we reveal narrow spectral features precursory of dynamical instabilities due to the intrinsic out-of-equilibrium nature of the system. This technique provides the missing tool for the quantitative study of quantum hydrodynamics in polariton fluids.

5 pages, 2 figures. Comments are welcome

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• Quantum fluids of light
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• Quantised Vortices in an Exciton-Polariton Fluid
• Quantum depletion of a homogeneous Bose-Einstein condensate
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Cited by in corpus (7)

• Spectrum of collective excitations of a quantum fluid of polaritons
• Optical isolators based on non-reciprocal four-wave mixing
• Photon-Pressure with an Effective Negative Mass Microwave Mode
• Analogue quantum simulation of the Hawking effect in a polariton superfluid
• Analogue gravitational lensing in optical Bose-Einstein condensates
• Metamorphoses of the flow past an obstacle of a resonantly-driven bistable polariton fluid
• Dark and thermal reservoir contributions to polariton sound velocity