Resolving quanta of collective spin excitations in a millimeter-sized ferromagnet.
Resolving quanta of collective spin excitations in a millimeter-sized ferromagnet.
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DOI：
10.1126/sciadv.1603150
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发表时间：
2017-07
期刊：
影响因子：
13.6
通讯作者：
Nakamura Y
中科院分区：
文献类型：
--
作者：
Lachance-Quirion D;Tabuchi Y;Ishino S;Noguchi A;Ishikawa T;Yamazaki R;Nakamura Y
通过对超导量子比特的测量，观察到铁磁体中集体自旋激发的量子数。在混合量子电路中结合不同的物理系统为量子技术开辟了新的可能性。在量子磁振子中，被称为磁子的铁磁体中的集体激发模的量子与量子比特相干地相互作用，从而获得磁振子的量子现象。我们使用这种结构来探测毫米大小的铁磁晶体中集体自旋激发的量子。更具体地说，我们通过测量强色散区中具有混合系统的超导量子比特的光谱测量来解决磁振子数态。这使我们能够探测到铁磁体的磁矩的变化，相当于在1019个自旋之间翻转一个自旋。我们的演示突出了混合量子系统在为量子传感和量子信息处理提供强大工具方面的优势。
Quanta of collective spin excitations are observed in a ferromagnet by measurements of a superconducting quantum bit. Combining different physical systems in hybrid quantum circuits opens up novel possibilities for quantum technologies. In quantum magnonics, quanta of collective excitation modes in a ferromagnet, called magnons, interact coherently with qubits to access quantum phenomena of magnonics. We use this architecture to probe the quanta of collective spin excitations in a millimeter-sized ferromagnetic crystal. More specifically, we resolve magnon number states through spectroscopic measurements of a superconducting qubit with the hybrid system in the strong dispersive regime. This enables us to detect a change in the magnetic moment of the ferromagnet equivalent to a single spin flipped among more than 1019 spins. Our demonstration highlights the strength of hybrid quantum systems to provide powerful tools for quantum sensing and quantum information processing.