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.

玻色-爱因斯坦凝聚的量子力学现象导致了许多有趣而重要的效应。 在4 He中，它导致了一种超流体，其中液体可以以粘性流动并在没有损失的情况下传输热量。 在某些金属中，它导致超导性，其中电流被无损耗地传输-提供了电力分配的潜力，而没有当前电力线中发生的损耗。 在超冷原子中也观察到了BEC，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迷人和重要的行为。 在这个项目中，我们将尝试在嵌入固体分子氢的氢原子中产生玻色爱因斯坦凝聚。这些研究将在超低温（低于绝对零度以上0.1度）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方面的培训，这些技术与量子计算等许多物理领域有关。 开展了积极的外联方案。继续与研究生举行会议，接待大专生访问，并参加科学展览会。例如，首席研究员在得克萨斯A M物理和工程节上进行公开讲座并进行演示。这个节日通常有来自德克萨斯州和其他州的5000多名学生参加。 在强磁场（4.6Tesla，共振频率130 GHz）中，用电子自旋共振方法研究了嵌入固体分子氢薄膜中的氢原子的性质。用于这些测量的光谱仪已完全投入使用。稀释冰箱现已就位，可将样品冷却至低于100 mK的温度。在较低的温度和较高的氢原子浓度下，为了达到完全的玻色-爱因斯坦凝聚，研究了以前观察到的核自旋极化与玻尔兹曼分布的大偏离。虽然在先前的实验中发现自旋晶格弛豫是几个小时，但不可能完全饱和两个最低超精细状态之间的过渡。这种异常行为进行了充分的调查。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，研究了不同薄膜衬底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.