This paper demonstrates a novel microwave frequency conversion method in a hybrid quantum system integrating nitrogen-vacancy (NV) centers in diamond with a magnetic thin film (CoFeB). The method achieves a wide conversion bandwidth (0.1–12 GHz), up to 25th-order frequency conversion, and is applied for frequency detection and qubit coherent control. Unlike traditional techniques based on nonlinear electric response, this approach utilizes nonlinear magnetic response in spintronic devices, originating from symmetry breaking in domain walls. The method's adaptability to other spintronic devices and spin qubits expands the application scope of spintronics and provides a promising on-chip platform for coupling quantum systems.

Jiahao Wu, Jiacheng Liu, Zheyu Ren, Man Yin Leung, Wai Kuen Leung, Kin On Ho, Xiangrong Wang, Qiming Shao, Sen Yang