Submerged-Shell Atoms Trapped in Noble Gas Solids for Quantum Information and Measurement

该项目将对捕获在固化惰性气体中的中性Tu原子进行光学和红外光谱分析，惰性气体是化学上不活泼的固体，有时被称为晶体。被捕获的铊原子可以用激光激发，这样就可以测量原子能级之间的跃迁频率。Tu之所以被选中，是因为它的电子构型不同寻常，在原子核附近的f壳层中包含价电子。与其他物种不同的是，当被困在晶体中时，它们的能级会被大幅加宽，而稀土元素的能级会被分解成可分解的成分。该项目将使用一套新的光谱技术来揭示被捕获在固体Ar和Ne中的Tu原子的完整能级图，这为将它们的独特性质用作纳米级局部环境的探测器或用作量子设备中的纠缠元素铺平了道路。该项目具有对量子信息科学和测量产生更广泛影响的巨大潜力，并将有助于对学生进行表面科学、低温、光学和原子物理方面的教育。该项目的动机特别是最近的观察，即1140 nm处f壳层之间的磁偶极跃迁可以窄至1.5 GHz，即使在人群中平均也是如此。此外，在GHz尺度上没有人口不均匀的迹象，这表明随着进一步的冷却，可能会获得MHz线宽。例如，这比钻石nv中心的不均匀性要窄得多，后者支持在气相光谱学中看到的这样一个概念，即水下f壳层与周围环境的相互作用比S或p能级要少得多。这为量子信息和测量提供了一个新的平台，其中频率分辨率允许详细的光学泵浦方案，即使原子在亚纳米级保持在适当的位置，与测量目标处于同一位置，和/或通过一个普遍兼容的过程直接集成到量子硬件中，只需一个步骤：凝聚惰性气体固体和共沉积Tu。特别值得一提的是，高密度和高均匀性在量子信息应用和观测超辐射等相干效应方面具有广阔的应用前景。为了研究这些可能性，将进行一系列实验，以确定固态Ar和Ne主机中Tu的低温线宽，解决晶场分裂产生的基态亚结构，增加最大光子循环率，并尝试感知玻璃衬底附近的环境。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will perform optical and infrared spectroscopy of neutral thulium atoms trapped in solidified noble gases, which are chemically inert solids sometimes called cryocrystals. The trapped thulium atoms may be excited with a laser, which allows transition frequencies between the atomic energy levels to be measured. Thulium is chosen because of its unusual electron configuration, which contains valence electrons in the f-shell near the nucleus. Unlike other species whose energy levels are substantially broadened when trapped in a cryocrystal, thulium energy levels are split into resolvable components. This project will employ a new set of spectroscopy techniques to uncover the complete energy level diagram for thulium atoms trapped in solid argon and neon, which paves the way for using their unique properties as probes of the local environment at nanometer scale, or as entangled elements in a quantum device. The project has great potential for broader impacts to quantum information science and measurement, and will contribute to education of students in surface science, cryogenics, optics, and atomic physics.This project is motivated in particular from recent observations that the magnetic dipole transition between f shells at 1140 nm can be as narrow as 1.5 GHz, even when averaged over a population. Furthermore, there is no indication of population inhomogeneity at the GHz scale, suggesting that with further cooling, MHz linewidths might be obtained. This is significantly narrower than, for example, the inhomogeneity in diamond NV centers, which supports the notion, seen in gas phase spectroscopy, that submerged f shells interact much less with the surrounding environment than s or p levels. This suggests a novel platform for quantum information and measurement, where frequency resolution permits detailed optical pumping schemes, even as atoms are held in place at the sub-nanometer scale, co-located with measurement targets, and/or directly integrated into quantum hardware via a universally compatible process requiring a single step: condensing noble gas solids with co-deposition of thulium. In particular, the high density combined with homogeneity are promising for quantum information applications and for observing coherent effects such as superradiance. To investigate these possibilities, a series of experiments will be performed to determine the low-temperature linewidth of thulium in solid argon and neon hosts, to resolve ground state substructure coming from crystal field splitting, to increase the maximum photon cycling rate, and to attempt to sense the environment near a glass substrate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.