New experiments to measure rotational speed may rewrite physics textbooks

Researchers have used quantum sensors to explore new particle interactions at microscopic distances, providing groundbreaking results that expand the scope of the Standard Model in physics.

A research team led by Academician Du Jiangfeng and Professor Rong Xing from the University of Science and Technology of China (USTC), part of the Chinese Academy of Sciences (CAS), in collaboration with Professor Jiao Man from Zhejiang University, used solid-state quantum spin sensors to investigate spin-velocity-dependent exotic interactions (SSIVDs) in short force ranges. Their study reports new experimental results on spin-electron interactions and is published in Physical review letters.

The Standard Model is a highly successful theoretical framework in particle physics, describing fundamental particles and four fundamental interactions. However, the Standard Model still cannot explain some important observational facts in current cosmology, such as dark matter and dark energy.

Some theories suggest that the new particles could act as diffusion devices, transmitting new interactions between Standard Model particles. At present, there is a lack of experimental research on new velocity-related interactions between cycles, especially in the relatively small force-distance range, where experimental verification is almost non-existent.

Experimental results of the study. Credit: Du et al.

Experimental setup and methodology

The researchers designed an experimental device equipped with two diamonds. A high-quality array of nitrogen vacancies was prepared on the surface of each diamond using chemical vapor deposition. The electron spin in one group of the nitrogen vacancy acts as a spin sensor, while the other acts as a spin source.

The researchers investigated novel interaction effects between the speed-dependent spin of electrons at the micrometer scale by coherently manipulating the spin quantum states and relative velocities of two diamond NV clusters. First, they used a spin sensor to characterize the interaction of a magnetic dipole with a spin source as a reference. Then, by modulating the vibration of the spin source and performing lock-in detection and orthogonal phase analysis, they measured the SSIVDs.

For two new interactions, the researchers made the first experimental detection in the force range of less than 1 cm and less than 1 km, respectively, and obtained valuable experimental data.

As the editor noted, “The results provide new insights for the quantum sensing community to explore fundamental interactions by exploiting the compact, flexible, and spin-sensitive features of the solid state.”

Reference: “New constraints on exotic spin-velocity-dependent interactions with solid-state quantum sensors” by Yu Huang, Hang Liang, Man Jiao, Bai Yu, Xiangyu Yi, Yijin Xie, Yi-Fu Cai, Zhang-Kui Duan, Ya Wang, Xingrong, and Jiangfeng Du, April 30, 2024, Physical Review Letters.
DOI: 10.1103/PhysRevLett.132.180801