Dynamical d-wave condensation of exciton-polaritons in a two-dimensional square-lattice potential
Dynamical d-wave condensation of exciton-polaritons in a two-dimensional square-lattice potential
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DOI：
10.1038/nphys2012
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发表时间：
2011-09-01
期刊：
影响因子：
19.6
通讯作者：
Yamamoto, Yoshihisa
中科院分区：
文献类型：
--
作者：
Kim, Na Young;Kusudo, Kenichiro;Yamamoto, Yoshihisa
宏观秩序表现为许多相互作用的粒子的集体行为。主要的例子是氦的超流动性(1)，原子玻色-爱因斯坦凝聚(2)，s波(3)和d波超导性(4)以及金属-绝缘体跃迁(5)。这些物理性质与自旋和电荷自由度密切相关，并因轨道结构而大大丰富(6)。此外，玻色子的高轨道态表现出与实值玻色子基态不同的奇异阶数(7)。近年来，人们利用光学晶格中的原子凝聚物研究了许多相关现象（8-10），但高轨道阶的实验观测仅限于动量空间（11,12）。在这里，我们建立了微腔激子-极化子凝聚体作为探索高轨道阶的有希望的替代方案。我们观察了方形晶格上d轨道凝聚体的形成，并从实空间和动量空间的居群分布来表征它们的相干性。
Macroscopic order appears as the collective behaviour of many interacting particles. Prime examples are superfluidity in helium(1), atomic Bose-Einstein condensation(2), s-wave(3) and d-wave superconductivity(4) and metal-insulator transitions(5). Such physical properties are tightly linked to spin and charge degrees of freedom and are greatly enriched by orbital structures(6). Moreover, high-orbital states of bosons exhibit exotic orders distinct from the orders with real-valued bosonic ground states(7). Recently, a wide range of related phenomena have been studied using atom condensates in optical lattices(8-10), but the experimental observation of high-orbital orders has been limited to momentum space(11,12). Here we establish microcavity exciton-polariton condensates as a promising alternative for exploring high-orbital orders. We observe the formation of d-orbital condensates on a square lattice and characterize their coherence properties in terms of population distributions both in real and momentum space.