文章基本信息

标题：Power-law decay of the spatial correlation function in exciton-polariton condensates
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作者：Georgios Roumpos ; Michael Lohse ; Wolfgang H. Nitsche 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2012
卷号：109
期号：17
页码：6467-6472
DOI：10.1073/pnas.1107970109
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We create a large exciton-polariton condensate and employ a Michelson interferometer setup to characterize the short- and long-distance behavior of the first order spatial correlation function. Our experimental results show distinct features of both the two-dimensional and nonequilibrium characters of the condensate. We find that the gaussian short-distance decay is followed by a power-law decay at longer distances, as expected for a two-dimensional condensate. The exponent of the power law is measured in the range 0.9-1.2, larger than is possible in equilibrium. We compare the experimental results to a theoretical model to understand the features required to observe a power law and to clarify the influence of external noise on spatial coherence in nonequilibrium phase transitions. Our results indicate that Berezinskii-Kosterlitz-Thouless-like phase order survives in open-dissipative systems.
关键词：quantum well excitons ; semiconductor microcavities