Quantum Error-Correction-Enhanced Magnetometer Overcoming the Limit Imposed by Relaxation
Quantum Error-Correction-Enhanced Magnetometer Overcoming the Limit Imposed by Relaxation
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DOI：
10.1103/physrevlett.115.200501
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发表时间：
2015-11-09
影响因子：
8.6
通讯作者：
Retzker, Alex
中科院分区：
文献类型：
--
作者：
Herrera-Marti, David A.;Gefen, Tuvia;Retzker, Alex
在量子传感协议中，量子误差校正可以用于校正高频噪声，因为校正过程不依赖于噪声频谱的实际形状。因此，它提供了一种强大的方式来补充通常的重新聚焦技术。弛豫对现有量子传感器的灵敏度有一个基本的限制，不能通过动态解耦来克服。克服这个问题的唯一方法是利用量子纠错码。我们提出了一种包含近似量子误差校正的超导磁强计设计，其中信号由两个量子比特的哈密顿项产生。这两个量子位元项是由两个transmon量子位元之间的可调谐耦合器的动力学提供的。为了获得足够快的校正，可以将器件的相干时间延长到超过松弛限制。
When incorporated in quantum sensing protocols, quantum error correction can be used to correct for high frequency noise, as the correction procedure does not depend on the actual shape of the noise spectrum. As such, it provides a powerful way to complement usual refocusing techniques. Relaxation imposes a fundamental limit on the sensitivity of state of the art quantum sensors which cannot be overcome by dynamical decoupling. The only way to overcome this is to utilize quantum error correcting codes. We present a superconducting magnetometry design that incorporates approximate quantum error correction, in which the signal is generated by a two qubit Hamiltonian term. This two-qubit term is provided by the dynamics of a tunable coupler between two transmon qubits. For fast enough correction, it is possible to lengthen the coherence time of the device beyond the relaxation limit.