Light-matter decoupling and A(2) term detection in superconducting circuits.
Light-matter decoupling and A(2) term detection in superconducting circuits.
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DOI：
10.1038/srep16055
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发表时间：
2015-11-04
影响因子：
4.6
通讯作者：
De Liberato S
中科院分区：
文献类型：
--
作者：
García-Ripoll JJ;Peropadre B;De Liberato S
在存在传播微波的情况下，超导量子位的自发发射和受激发射源自有效的光-物质相互作用，与原子情况类似，可以包含与平方矢量势 A2 成比例的反磁项。在目前的工作中，我们证明抗磁项强度的增加会导致量子位与电磁场的有效解耦，并且这种效应在任何量子位-光子耦合范围内都可以观察到。为了测量这种效应，我们建议使用悬挂在传输线上的传输器，其中 A2 项的相对强度由量子位线分离控制。我们表明，在短距离内，在线路上悬浮传输的自发发射率会随着这种分离而增加，而不是减少。
The spontaneous and stimulated emission of a superconducting qubit in the presence of propagating microwaves originates from an effective light-matter interaction that, similarly to the case of the atomic case, can contain a diamagnetic term proportional to the square vector potential A2. In the present work we prove that an increase in the strength of the diamagnetic term leads to an effective decoupling of the qubit from the electromagnetic field, and that this effect is observable at any range of qubit-photon coupling. To measure this effect we propose to use a transmon suspended over a transmission line, where the relative strength of the A2 term is controlled by the qubit-line separation. We show that the spontaneous emission rate of the suspended transmon onto the line can, at short distances, increase with such a separation, instead of decreasing.