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arXiv 1206.3597cond-mat.mtrl-sci
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氮化铀中氮原子的量子振荡

Quantum oscillations of nitrogen atoms in uranium nitride

A. A. Aczel, G. E. Granroth, G. J. MacDougall, W. J. L. Buyers, D. L. Abernathy, G. D. Samolyuk, G. M. Stocks, S. E. Nagler

摘要:

对应于声学或光学单声子模式的晶体固体的振动激发在诸如中子光谱学的测量中表现为尖锐的特征。相比之下,多声子激发通常产生复杂、微弱且无特征的响应。在这里,我们提出了飞行时间中子散射测量的二元固体氮化铀(UN),显示良好定义的,等间距的,高能量的振动模式,除了通常的声子。光谱是一个单一的原子,各向同性量子谐振子和特征的独立运动的轻氮原子,每个发现在一个八面体笼的重铀原子。这是对量子力学中一个基本的、精确可解的问题的一个意想不到的、美丽的实验实现。这也有实际的意义,因为在设计计划使用UN作为燃料的第四代核反应堆时必须考虑振荡器模式。

英文摘要:

The vibrational excitations of crystalline solids corresponding to acoustic or optic one phonon modes appear as sharp features in measurements such as neutron spectroscopy. In contrast, many-phonon excitations generally produce a complicated, weak, and featureless response. Here we present time-of-flight neutron scattering measurements for the binary solid uranium nitride (UN), showing well-defined, equally-spaced, high energy vibrational modes in addition to the usual phonons. The spectrum is that of a single atom, isotropic quantum harmonic oscillator and characterizes independent motions of light nitrogen atoms, each found in an octahedral cage of heavy uranium atoms. This is an unexpected and beautiful experimental realization of one of the fundamental, exactly-solvable problems in quantum mechanics. There are also practical implications, as the oscillator modes must be accounted for in the design of generation IV nuclear reactors that plan to use UN as a fuel.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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