Emergence of quantum correlations from interacting fibre-cavity polaritons

• Published in: Nature materials Vol. 18; no. 3; pp. 213 - 218
• Main Authors: Muñoz-Matutano, Guillermo, Wood, Andrew, Johnsson, Mattias, Vidal, Xavier, Baragiola, Ben Q., Reinhard, Andreas, Lemaître, Aristide, Bloch, Jacqueline, Amo, Alberto, Nogues, Gilles, Besga, Benjamin, Richard, Maxime, Volz, Thomas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2019; Nature Publishing Group
• Subjects: 140/125; 639/766/1130; 639/766/119; 639/766/400; 639/766/483; Autocorrelation functions; Biomaterials; Chemistry and Materials Science; Condensed Matter; Condensed Matter Physics; Correlation; Emergence; Letter; Materials Science; Microcavities; Nanotechnology; Optical and Electronic Materials; Photons; Physics; Polaritons; Quantum Gases; Quantum Physics; Quantum theory
• ISSN: 1476-1122; 1476-4660; 1476-4660
• DOI: 10.1038/s41563-019-0281-z

Over the past decade, exciton-polaritons in semiconductor microcavities have revealed themselves as one of the richest realizations of a light-based quantum fluid 1 , subject to fascinating new physics and potential applications 2 – 6 . For instance, in the regime of large two-body interactions, polaritons can be used to manipulate the quantum properties of a light field 7 – 9 . In this work, we report on the emergence of quantum correlations in laser light transmitted through a fibre-cavity polariton system. We observe a dispersive shape of the autocorrelation function around the polariton resonance that indicates the onset of this regime. The weak amplitude of these correlations indicates a state that still remains far from a low-photon-number state. Nonetheless, given the underlying physical mechanism 7 , our work opens up the prospect of eventually using polaritons to turn laser light into single photons. Two-photon correlation measurements in a resonantly excited fibre-cavity polariton system stay below the classical limit for zero time delay, suggesting quantum correlations between the polaritons.