Spin coherence and optical properties of alkali-metal atoms in solid parahydrogen
Spin coherence and optical properties of alkali-metal atoms in solid parahydrogen
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DOI：
10.1103/physreva.100.063419
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发表时间：
2019-10
影响因子：
2.9
通讯作者：
S. Upadhyay;Ugne Dargyte;V. D. Dergachev;R. Prater;S. Varganov;T. Tscherbul;D. Patterson;J. Weinstein
中科院分区：
文献类型：
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作者：
S. Upadhyay;Ugne Dargyte;V. D. Dergachev;R. Prater;S. Varganov;T. Tscherbul;D. Patterson;J. Weinstein
我们对捕获在固体仲氢基质中的39K、85Rb、87Rb和133Cs原子的自旋相干性质进行了联合实验和理论研究。我们用光学泵浦来制备注入原子的自旋态，并用圆二向色性来测量它们的自旋态。光抽运信号显示出数量级的差异，这取决于基质生长条件和原子种类。我们测量了碱金属原子自旋态的系综横向弛豫时间(T2*)。不同的碱物种表现出明显不同的T2*时间，从87Rb的高MF态的亚微秒相干时间到39K的~100微秒的相干时间不等。这是已报道的高密度(n>；10^16 cm^-3)电子自旋系统最长的系综T2*次。为了解释这些观测结果，我们发展了弱相互作用固体基质中^2S原子超精细跃迁的非均匀展宽理论。我们计算的系综横向弛豫时间与实验符合得很好，并在未来的工作中提出了延长相干时间的方法。
We present a joint experimental and theoretical study of spin coherence properties of 39K, 85Rb, 87Rb, and 133Cs atoms trapped in a solid parahydrogen matrix. We use optical pumping to prepare the spin states of the implanted atoms and circular dichroism to measure their spin states. Optical pumping signals show order-of-magnitude differences depending on both matrix growth conditions and atomic species. We measure the ensemble transverse relaxation times (T2*) of the spin states of the alkali-metal atoms. Different alkali species exhibit dramatically different T2* times, ranging from sub-microsecond coherence times for high mF states of 87Rb, to ~100 microseconds for 39K. These are the longest ensemble T2* times reported for an electron spin system at high densities (n > 10^16 cm^-3). To interpret these observations, we develop a theory of inhomogenous broadening of hyperfine transitions of ^2S atoms in weakly-interacting solid matrices. Our calculated ensemble transverse relaxation times agree well with experiment, and suggest ways to longer coherence times in future work.