Studies of Atomic Hydrogen Contained in Solid Molecular Hydrogen Isotopes

固体分子氢同位素中所含原子氢的研究

• 批准号: 1707565
• 负责人: David Lee
• 金额: $ 53万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707565&HistoricalAwards=false
• 关键词: Studies; Atomic; Hydrogen; Contained; Solid

Non-technical AbstractThe quantum mechanical phenomena of Bose Einstein Condensation leads to many fascinating and important effects. In 4He it leads to a superfluid where the liquid can flow with viscosity and transport heat without loss. In some metals it leads to superconductivity where electric currents are carried without loss - offering the potential for power distribution without the losses that occur in current power lines. BEC has also been observed in super-cooled atoms which could lead to more precise atomic clocks that power the global positioning system. Other, yet to be discovered systems, may show equally fascinating and important behavior. In this project we will attempt to produce a Bose Einstein Condensate in hydrogen atoms embedded in solid molecular hydrogen. The studies will take place at ultra-low temperature (below 0.1 degrees above absolute zero) and utilize microwave magnetic resonance techniques. This work will provide training in state-of-the-art low temperature and microwave techniques which are relevant in many areas of physics such as quantum computing. An active outreach program is pursued. Meetings with graduate students, visits by junior college students and participation in science fairs continues. For example, the principal investigator gives public lectures at the Texas A & M Physics and Engineering Festival with demonstrations. The festival is typically attended by more than 5000 students from all over the state of Texas and beyond. Technical AbstractThe properties of hydrogen atoms embedded in solid molecular hydrogen films are studied by electron spin resonance in a high magnetic field (4.6 Tesla, resonant frequency 130 GHz) corresponding to 2mm waves. The spectrometer for these measurements is fully operational. A dilution refrigerator is now in place to cool the samples to temperatures below 100 mK. The large departure of the polarization of the nuclear spins from the Boltzmann distribution observed previously are investigated down to lower temperatures and at higher hydrogen atom concentrations in an attempt to reach full Bose-Einstein condensation. Although in previous experiments the spin-lattice relaxation was found to be several hours, it was not possible to fully saturate the transition between the two lowest hyperfine states. This anomalous behavior is fully investigated. Hole burning experiments in a magnetic field gradient also are performed to determine the hydrogen atom mobility as Bose-Einstein condensation occurs. Finally, the effect of different film substrates on the departure from Boltzmann statistics of hydrogen atoms are studied.

非技术摘要玻色爱因斯坦凝聚的量子力学现象导致了许多令人着迷且重要的效应。 在 4He 中，它形成了一种超流体，其中液体可以具有粘度流动并无损失地传输热量。 在某些金属中，它会导致超导性，使电流能够无损耗地传输，从而提供了配电的潜力，而不会出现当前电源线中出现的损耗。 BEC 也在超冷原子中被观察到，这可能会导致更精确的原子钟为全球定位系统提供动力。 其他尚未被发现的系统可能会表现出同样令人着迷且重要的行为。 在这个项目中，我们将尝试用嵌入固体氢分子中的氢原子生产玻色爱因斯坦凝聚。研究将在超低温（绝对零以上 0.1 度以下）下进行，并利用微波磁共振技术。 这项工作将提供最先进的低温和微波技术的培训，这些技术与量子计算等许多物理领域相关。 正在开展积极的外展计划。与研究生的会面、专科生的访问以及参加科学博览会的活动仍在继续。例如，首席研究员在德克萨斯农工大学物理与工程节上进行公开讲座并进行演示。该节日通常有来自德克萨斯州及其他地区的 5000 多名学生参加。 技术摘要通过在对应于2毫米波的高磁场（4.6特斯拉，谐振频率130 GHz）中的电子自旋共振来研究嵌入固体分子氢膜中的氢原子的性质。用于这些测量的光谱仪已完全运行。稀释冰箱现已到位，可将样品冷却至 100 mK 以下的温度。核自旋极化与先前观察到的玻尔兹曼分布的巨大偏离被研究到较低的温度和较高的氢原子浓度，以试图达到完全的玻色-爱因斯坦凝聚。尽管在之前的实验中发现自旋晶格弛豫需要几个小时，但不可能使两个最低超精细态之间的转变完全饱和。这种异常行为已得到充分调查。还进行了磁场梯度中的烧孔实验，以确定玻色-爱因斯坦凝聚发生时氢原子的迁移率。最后，研究了不同薄膜基材对氢原子偏离玻尔兹曼统计的影响。

项目成果

Luminescence of molecular nitrogen in cryogenic plasmas

低温等离子体中分子氮的发光

• DOI: 10.1063/1.5111300
• 发表时间: 2019
• 期刊: Low Temperature Physics
• 影响因子: 0.8
• 作者: Boltnev, R. E.;Bykhalo, I. B.;Khmelenko, V. V.;Krushinskaya, I. N.;Lee, D. M.;McColgan, P. T.;Sheludiakov, S.;Pelmenev, A. A.
• 通讯作者: Pelmenev, A. A.

Luminescence of molecular nitrogen nanoclusters containing stabilized nitrogen, oxygen, hydrogen, and deuterium atoms

含有稳定氮、氧、氢和氘原子的氮分子纳米团簇的发光

• DOI: 10.1088/1742-6596/969/1/012007
• 发表时间: 2018
• 期刊: Journal of Physics: Conference Series
• 作者: McColgan, P T;Meraki, A;Boltnev, R E;Sheludiakov, S;Lee, D M;Khmelenko, V V
• 通讯作者: Khmelenko, V V

Evidence for melting of HD and D2 clusters in solid neon below 1 K

HD 和 D2 团簇在低于 1 K 的固体氖中熔化的证据

• DOI: 10.1103/physrevb.99.174514
• 发表时间: 2019
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Sheludiakov, S.;Ahokas, J.;Järvinen, J.;Lehtonen, L.;Vasiliev, S.;Dmitriev, Yu. A.;Lee, D. M.;Khmelenko, V. V.
• 通讯作者: Khmelenko, V. V.

Electron spin resonance study of atomic hydrogen stabilized in solid neon below 1 K

1 K 以下固体氖中稳定的原子氢的电子自旋共振研究

• DOI: 10.1103/physrevb.97.104108
• 发表时间: 2018
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Sheludiakov, S.;Ahokas, J.;Järvinen, J.;Lehtonen, L.;Vasiliev, S.;Dmitriev, Yu. A.;Lee, D. M.;Khmelenko, V. V.
• 通讯作者: Khmelenko, V. V.

Luminescence of Molecular Nitrogen Nanoclusters Containing Stabilized Atoms

含有稳定原子的分子氮纳米团簇的发光

• DOI: 10.1021/acs.jpca.7b09661
• 发表时间: 2017
• 期刊: The Journal of Physical Chemistry A
• 作者: McColgan, Patrick T.;Meraki, Adil;Boltnev, Roman E.;Lee, David M.;Khmelenko, Vladimir V.
• 通讯作者: Khmelenko, Vladimir V.