Abstract: Ultrasensitive atomic magnetometer and co-magnetometer have provided powerful tools for studies on the material world. These devices are widely used in imaging of biomagnetic signals and frontier physics research, such as magnetocardiography, magnetoencephalography, search for dark matter and the fifth force, measurement of permanent electric dipole moment, and violation of fundamental symmetry, and are urgently needed in national security areas such as magnetic anomaly detection and high-precision inertial navigation systems. Improving sensitivity records and building ultra-low magnetic field environment are pivotal for further research of fundamental physics, biomagnetic imaging and major national needs. Firstly, schematic introductions of ultrasensitive atomic magnetometer and co-magnetometer as well as their basic applications are presented, including the working principle, experiment setup, and theoretical model. Secondly, schematic summaries of atomic magnetometer and magnetic shield room are presented, specifying the ways to improve the performance. Finally, considering the basic research on the extremely weak magnetic field environment is still very scarce in spite of fruitful results of research on physical properties in the strong magnetic field environment, this paper proposes a basic research concept of zero-magnetism science. Based on the facilities of ultrasensitive atomic magnetometer, co-magnetometer and magnetic shield room, the technologies of ultra-low magnetic field environment, ultrasensitive magnetic measurement, and precise magnetic field manipulation are utilized to conduct the basic scientific research including zero-magnetism medicine, zero-magnetism biology, zero-magnetism chemistry and zero-magnetism materials science, hoping to develop a theoretical system for zero-magnetism science.

Key words: ultra-weak magnetic field and inertial rotation measurement, magnetic shielded space, biomagnetic imaging, exploration beyond standard model, zero-magnetism science