Using muons to probe low energy quantum fluctuations in the mineral Linarite

Novel, low dimensional magentic systems tend to be dominated by quantum behaviour. They serve as excellent test beds for theoretical models, but also signposting chemical structures by which to achieve different desired properties. There however some chemical structures that prove hard to predicit and synthesise within the lab, and often nature can help us out by providing naturally occuring minerals. One such example is linarite that has recieved much attention over the years; a compund that is dominated by 1D chains of Cu(II) ions.There is speculation as to whether quantum fluctuations are present and supress magnetic order or cause the magentic order to be weak. Recent neutron experiments have shown that there is very weak inter-chain coupling, but is it an order of magentitude lower then the intra-chain coupling. Muons are an ideal probe for studying order as well as any magentic flucutations and can provide definative answers on the low energy fluctuations within the system.

新型低维磁性系统通常以量子行为为核心特征，它们既是理论模型的优质测试平台，也能为制备具有目标物性的化学结构提供设计指引。然而，部分化学结构在实验室中难以预测与合成，此时自然界产出的矿物往往能为我们提供解决方案。其中，纤铜铅矿（linarite）就是多年来广受关注的一例，该化合物以铜(II)离子构成的一维链为结构主体。学界此前一直存在争议：该体系中是否存在量子涨落，其究竟会抑制磁有序，还是仅导致磁有序强度减弱？近期中子实验结果表明，该体系的链间耦合极弱，其强度甚至比链内耦合低一个数量级。μ子（Muons）是研究磁有序与各类磁涨落的理想探针，能够为该体系内的低能涨落问题提供确定性的解答。