Liu Yu-xi, Sun Hui-Chen, Peng Z H, Miranowicz Adam, Tsai J S, Nori Franco
1] Institute of Microelectronics, Tsinghua University, Beijing 100084, China [2] Tsinghua National Laboratory for Information Science and Technology (TNList), Beijing 100084, China [3] CEMS, RIKEN, Saitama 351-0198, Japan.
1] Institute of Microelectronics, Tsinghua University, Beijing 100084, China [2] CEMS, RIKEN, Saitama 351-0198, Japan.
Sci Rep. 2014 Dec 9;4:7289. doi: 10.1038/srep07289.
Three-wave mixing in second-order nonlinear optical processes cannot occur in atomic systems due to the electric-dipole selection rules. In contrast, we demonstrate that second-order nonlinear processes can occur in a superconducting quantum circuit (i.e., a superconducting artificial atom) when the inversion symmetry of the potential energy is broken by simply changing the applied magnetic flux. In particular, we show that difference- and sum-frequencies (and second harmonics) can be generated in the microwave regime in a controllable manner by using a single three-level superconducting flux quantum circuit (SFQC). For our proposed parameters, the frequency tunability of this circuit can be achieved in the range of about 17 GHz for the sum-frequency generation, and around 42 GHz (or 26 GHz) for the difference-frequency generation. Our proposal provides a simple method to generate second-order nonlinear processes within current experimental parameters of SFQCs.
由于电偶极选择定则，二阶非线性光学过程中的三波混频在原子系统中无法发生。相比之下，我们证明当通过简单改变外加磁通量打破势能的反演对称性时，二阶非线性过程可以在超导量子电路（即超导人造原子）中发生。特别地，我们表明通过使用单个三能级超导磁通量子电路（SFQC），可以在微波波段以可控方式产生差频和和频（以及二次谐波）。对于我们提出的参数，该电路在产生和频时的频率可调范围约为17 GHz，在产生差频时的频率可调范围约为42 GHz（或26 GHz）。我们的提议提供了一种在SFQC的当前实验参数范围内产生二阶非线性过程的简单方法。
