Researchers have used quantum sensors to study new particle interactions at microscale distances and announced groundbreaking discoveries that expand the scope of the Standard Model in physics.
A research team led by Academician Du Jiangfeng and Professor Rong Xing of the University of Science and Technology of China (USTC) under the Chinese Academy of Sciences (CAS), in collaboration with Professor Jiao Man of Zhejiang University, has used solid-state spin quantum sensors to investigate exotic spin-spin velocity dependent interactions (SSIVD) in the short force range. Their work reports new experimental findings on the interactions between electron spins, Physics Review Letter.
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 new particles could act as propagators to transmit new interactions between Standard Model particles. Currently, experimental work on the new spin-to-spin velocity-related interactions is lacking, especially in the relatively narrow range of force distances, and experimental verification is nearly non-existent.
Experimental setup and methods
The researchers designed an experimental setup with two diamonds, on the surface of which they prepared high-quality nitrogen-vacancy (NV) ensembles using chemical vapor deposition, with the electron spin of one NV ensemble acting as the spin sensor and the other as the spin source.
The researchers explored novel interaction effects between the velocity-dependent spins of electrons at the micrometer scale by coherently manipulating the spin quantum states and relative velocities of two diamond NV ensembles. First, they used a spin sensor to characterize the magnetic dipole interactions relative to the spin source. Then, they modulated the oscillation of the spin source and performed lock-in detection and phase quadrature analysis to measure the SSIVD.
The researchers performed the first experimental detection of two new interactions in the force ranges of less than 1 cm and 1 km, respectively, and obtained valuable experimental data.
“These results provide the quantum sensing community with new insights to explore fundamental interactions that exploit the compactness, flexibility, and sensitivity properties of solid-state spins,” the editors said.
Reference: Yue Huang, Hang Liang, Man Jiao, Pei Yu, Xiangyu Ye, Yijin Xie, Yi-Fu Cai, Chang-Kui Duan, Ya Wang, Xing Rong, Jiangfeng Du, “New constraints on exotic spin-spin rate dependent interactions from solid-state quantum sensors,” April 30, 2024; Physics Review Letter.
DOI: 10.1103/PhysRevLett.132.180801