Quantum superposition at the half-metre scale
Quantum superposition at the half-metre scale
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DOI：
10.1038/nature16155
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发表时间：
2015-12-24
期刊：
影响因子：
64.8
通讯作者：
Kasevich, M. A.
中科院分区：
文献类型：
--
作者：
Kovachy, T.;Asenbaum, P.;Kasevich, M. A.
量子叠加原理允许大质量粒子在遥远的位置上离域。虽然量子力学已被证明擅长描述微观世界，但量子叠加在扩展到宏观尺度时与现实和局部性的直观概念背道而驰（1），正如薛定谔猫的思想实验所证明的那样（2）。物质波干涉仪（3）分裂和重组波包以观察干涉，提供了一种在宏观尺度上探索叠加原理（4）和探索向经典物理学过渡（5）的方法。在这样的实验中，需要长的相互作用时间和大的动量分束器来阻碍大的波包分离，这会导致对失相和退相干的敏感性（1）。在这里，我们使用光脉冲原子干涉术（6，7）来实现量子干涉，在1秒的时间尺度上，波包间隔高达54厘米。这些结果将量子叠加推向了一个新的宏观领域，表明量子叠加在日常生活的距离和时间尺度上仍然是可能的。原子的亚纳开尔文温度和横向光学力的补偿使大的分离，同时保持28%的干涉对比度。除了在新的制度中测试叠加原理外，大量子叠加态对于用原子干涉仪更详细地探索引力至关重要。我们预计这些状态可以用来提高等效原理测试的灵敏度（8-12），测量引力阿哈罗诺夫-玻姆效应（13），并最终检测引力波（14）和与广义相对论相关的相移（12）。
The quantum superposition principle allows massive particles to be delocalized over distant positions. Though quantum mechanics has proved adept at describing the microscopic world, quantum superposition runs counter to intuitive conceptions of reality and locality when extended to the macroscopic scale(1), as exemplified by the thought experiment of Schrodinger's cat(2). Matter-wave interferometers(3), which split and recombine wave packets in order to observe interference, provide a way to probe the superposition principle on macroscopic scales(4) and explore the transition to classical physics(5). In such experiments, large wave-packet separation is impeded by the need for long interaction times and large momentum beam splitters, which cause susceptibility to dephasing and decoherence(1). Here we use light-pulse atom interferometry(6,7) to realize quantum interference with wave packets separated by up to 54 centimetres on a timescale of 1 second. These results push quantum superposition into a new macroscopic regime, demonstrating that quantum superposition remains possible at the distances and timescales of everyday life. The sub-nanokelvin temperatures of the atoms and a compensation of transverse optical forces enable a large separation while maintaining an interference contrast of 28 per cent. In addition to testing the superposition principle in a new regime, large quantum superposition states are vital to exploring gravity with atom interferometers in greater detail. We anticipate that these states could be used to increase sensitivity in tests of the equivalence principle(8-12), measure the gravitational Aharonov-Bohm effect(13), and eventually detect gravitational waves(14) and phase shifts associated with general relativity(12).