Makhonin Maxim, Delphan Anthonin, Song Kok Wee, Walker Paul, Isoniemi Tommi, Claronino Peter, Orfanakis Konstantinos, Rajendran Sai Kiran, Ohadi Hamid, Heckötter Julian, Assmann Marc, Bayer Manfred, Tartakovskii Alexander, Skolnick Maurice, Kyriienko Oleksandr, Krizhanovskii Dmitry
Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK.
Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4PY, UK.
Light Sci Appl. 2024 Feb 6;13(1):47. doi: 10.1038/s41377-024-01382-9.
Rydberg excitons (analogues of Rydberg atoms in condensed matter systems) are highly excited bound electron-hole states with large Bohr radii. The interaction between them as well as exciton coupling to light may lead to strong optical nonlinearity, with applications in sensing and quantum information processing. Here, we achieve strong effective photon-photon interactions (Kerr-like optical nonlinearity) via the Rydberg blockade phenomenon and the hybridisation of excitons and photons forming polaritons in a Cu2O-filled microresonator. Under pulsed resonant excitation polariton resonance frequencies are renormalised due to the reduction of the photon-exciton coupling with increasing exciton density. Theoretical analysis shows that the Rydberg blockade plays a major role in the experimentally observed scaling of the polariton nonlinearity coefficient as ∝ n for principal quantum numbers up to n = 7. Such high principal quantum numbers studied in a polariton system for the first time are essential for realisation of high Rydberg optical nonlinearities, which paves the way towards quantum optical applications and fundamental studies of strongly correlated photonic (polaritonic) states in a solid state system.
里德堡激子（凝聚态物质系统中里德堡原子的类似物）是具有大玻尔半径的高激发束缚电子 - 空穴态。它们之间的相互作用以及激子与光的耦合可能导致强光学非线性，在传感和量子信息处理中有应用。在此，我们通过里德堡阻塞现象以及在充满 Cu2O 的微谐振器中激子与光子形成极化激元的杂化实现了强有效光子 - 光子相互作用（类克尔光学非线性）。在脉冲共振激发下，由于随着激子密度增加光子 - 激子耦合的降低，极化激元共振频率被重整化。理论分析表明，对于主量子数高达 n = 7 的情况，里德堡阻塞在实验观测到的极化激元非线性系数与 n 成正比的标度关系中起主要作用。首次在极化激元系统中研究的这种高主量子数对于实现高里德堡光学非线性至关重要，这为固态系统中强关联光子（极化激元）态的量子光学应用和基础研究铺平了道路。
