Planck distribution of phonons in a Bose-Einstein condensate.
Planck distribution of phonons in a Bose-Einstein condensate.
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玻色-爱因斯坦凝聚体中声子的普朗克分布。
DOI：
10.1103/physrevlett.111.055301
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发表时间：
2013
影响因子：
8.6
通讯作者：
Jeff Steinhauer
中科院分区：
文献类型：
--
作者：
R. Schley;A. Berkovitz;S. Rinott;I. Shammass;A. Blumkin;Jeff Steinhauer
黑体发射光子的普朗克分布导致了量子理论的发展。类似的声子分布应该存在于玻色-爱因斯坦凝聚体中。我们观察了三维凝聚态中热声子的普朗克分布。这一观测结果对凝聚态的量子化激发的基本性质提供了重要的证实。与聚束效应相反，密度波动随着温度的升高而增加。这是由于声子数目的不守恒。在快速冷却的情况下，声子温度与周围的热云不平衡。在这种情况下，玻色-爱因斯坦凝聚体并不像之前认为的那么冷。这些测量是通过我们的原位k空间技术实现的。
The Planck distribution of photons emitted by a blackbody led to the development of quantum theory. An analogous distribution of phonons should exist in a Bose-Einstein condensate. We observe this Planck distribution of thermal phonons in a 3D condensate. This observation provides an important confirmation of the basic nature of the condensate's quantized excitations. In contrast to the bunching effect, the density fluctuations are seen to increase with increasing temperature. This is due to the nonconservation of the number of phonons. In the case of rapid cooling, the phonon temperature is out of equilibrium with the surrounding thermal cloud. In this case, a Bose-Einstein condensate is not as cold as previously thought. These measurements are enabled by our in situ k-space technique.