Chen Qiong, Wen Jun, Yang W L, Feng M, Du Jiangfeng
Opt Express. 2015 Jan 26;23(2):1615-26. doi: 10.1364/OE.23.001615.
By exchange of virtual microwave photon induced by a transmission line resonator, the nonlinear interaction between a nitrogen-vacancy-center ensemble (NVE) and a superconducting charge qubit is achieved in circuit quantum electrodynamics, where the nonlinear coupling results from the second order of the coupling between the magnetic field of the transmission line resonator and the charge qubit. In our case, the nonlinear coupling can be much enhanced by a factor of the total spin number in the NVE. As an application, we present a potentially practical scheme to realize the squeezing of the NVE using the nonlinear coupling, which is within reach of the currently available technology.
通过传输线谐振器诱导的虚拟微波光子交换，在电路量子电动力学中实现了氮空位中心系综（NVE）与超导电荷量子比特之间的非线性相互作用，其中非线性耦合源于传输线谐振器磁场与电荷量子比特之间耦合的二阶效应。在我们的案例中，非线性耦合可以通过NVE中的总自旋数因子得到显著增强。作为一个应用，我们提出了一种利用非线性耦合实现NVE压缩的潜在实用方案，这在当前可用技术范围内是可行的。
