Quantum states cohere and interfere. Atoms arranged imperfectly in a solid rarely display these properties. Here we demonstrate an exception in a disordered quantum magnet that divides itself into nearly isolated subsystems. We probe these coherent spin clusters by driving the system nonlinearly and measuring the resulting hole in the linear spectral response. The Fano shape of the hole encodes the incoherent lifetime as well as coherent mixing of the localized excitations. For the Ising magnet LiHosub0.045/subYsub0.955/subFsub4/sub, the quality factor Q for spectral holes can be as high as 100,000. We tune the dynamics by sweeping the Fano mixing parameter q through zero via the ac pump amplitude as well as a dc transverse field. The zero crossing of q is associated with a dissipationless response at the drive frequency. Identifying localized two-level systems in a dense and disordered magnet advances the search for qubit platforms emerging from strongly interacting, many-body systems.
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机译:量子态凝聚并干扰。在固体中不完全布置的原子很少显示这些性质。在这里,我们在无序的量子磁体中证明了一个例外,其分为几乎孤立的子系统。我们通过在线性光谱响应中驱动系统并测量所得到的孔来探测这些相干旋转簇。孔的扇形形状编码了非相干的寿命以及局部激励的相干混合。对于ising磁体Liho 0.045 sub> Y 0.955 sub> f 4 sub>,质量因子q用于光谱孔的质量因子q可以高达100,000。我们通过AC泵幅度以及DC横向场将Fano混合参数Q通过零以及DC横向区域来调谐动力学。 Q的零交叉与驱动频率的折射响应相关联。在密集和无序的磁体中识别局部的两级系统可以推进对从强烈交互,许多机身系统出现的Qubit平台的搜索。
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