Implementation of a quantum metamaterial using superconducting qubits
Implementation of a quantum metamaterial using superconducting qubits
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DOI：
10.1038/ncomms6146
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发表时间：
2014-10-01
影响因子：
16.6
通讯作者：
Ustinov, Alexey V.
中科院分区：
文献类型：
--
作者：
Macha, Pascal;Oelsner, Gregor;Ustinov, Alexey V.
实现超材料的关键问题是证明存在对应于超原子相干振荡的集体模式。自然材料中的原子与电磁场相互作用是量子二能级系统。人造量子二能级系统可以通过冷却到基态的超导非线性谐振器来实现。在这里，我们进行了一个实验，其中20个量子元原子，所谓的通量量子比特，被嵌入到微波谐振器中。我们观察到量子比特超材料施加的谐振器频率的色散位移和八个量子比特的集体谐振耦合。实现的原型代表了自然发生的自旋系综的介观极限，因此，我们证明了共振量子位系综的AC塞曼位移。所研究的系统构成了一个基本的量子超材料的实现在这个意义上，许多人工原子集体耦合到光子场的量子化模式。
The key issue for the implementation of a metamaterial is to demonstrate the existence of collective modes corresponding to coherent oscillations of the meta-atoms. Atoms of natural materials interact with electromagnetic fields as quantum two-level systems. Artificial quantum two-level systems can be made, for example, using superconducting nonlinear resonators cooled down to their ground state. Here we perform an experiment in which 20 of these quantum meta-atoms, so-called flux qubits, are embedded into a microwave resonator. We observe the dispersive shift of the resonator frequency imposed by the qubit metamaterial and the collective resonant coupling of eight qubits. The realized prototype represents a mesoscopic limit of naturally occurring spin ensembles and as such we demonstrate the AC-Zeeman shift of a resonant qubit ensemble. The studied system constitutes the implementation of a basic quantum metamaterial in the sense that many artificial atoms are coupled collectively to the quantized mode of a photon field.