Spontaneous breaking of spatial and spin symmetry in spinor condensates.
Spontaneous breaking of spatial and spin symmetry in spinor condensates.
复制标题
旋量凝聚中空间和自旋对称性的自发破缺。
DOI：
10.1103/physrevlett.105.135302
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发表时间：
2010
影响因子：
8.6
通讯作者：
C. Klempt
中科院分区：
文献类型：
--
作者：
M. Scherer;B. Lücke;G. Gebreyesus;O. Topic;F. Deuretzbacher;W. Ertmer;Luis Santos;J. Arlt;C. Klempt
量子涨落的参量放大是对称性自发破缺的基本机制。在我们的实验中，旋量凝聚体充当自旋模式的参量放大器，导致放大云中空间和自旋对称性的双重自发破缺。我们的实验允许在特定的空间贝塞尔样模式的放大的精确分析，允许详细了解的双重对称性破缺。在共振，创造涡旋-antivortex叠加，我们表明，圆柱形的空间对称性是自发打破，但相位压缩防止自旋对称性破缺。然而，如果非简并自旋模式有助于放大，量子干涉导致自旋相关的密度分布，因此自发形成的纵向磁化模式。
Parametric amplification of quantum fluctuations constitutes a fundamental mechanism for spontaneous symmetry breaking. In our experiments, a spinor condensate acts as a parametric amplifier of spin modes, resulting in a twofold spontaneous breaking of spatial and spin symmetry in the amplified clouds. Our experiments permit a precise analysis of the amplification in specific spatial Bessel-like modes, allowing for the detailed understanding of the double symmetry breaking. On resonances that create vortex-antivortex superpositions, we show that the cylindrical spatial symmetry is spontaneously broken, but phase squeezing prevents spin-symmetry breaking. If, however, nondegenerate spin modes contribute to the amplification, quantum interferences lead to spin-dependent density profiles and hence spontaneously formed patterns in the longitudinal magnetization.