Magnetic field sensing provides a powerful lens for understanding materials. By measuring magnetic fields one can discover the magnetic structure of a material, how electrical currents flow, and exotic phenomena such as superconductivity and topology. Most magnetic measurements until now have focused primarily on measuring the magnitude and direction of the field, just as a compass measures the earth’s magnetic field. However, more can be learned about materials if magnetic noise signals where the magnetic field fluctuates in time can be measured, and the average field is zero. Furthermore, many materials phenomena can be best characterized by measuring correlations in the magnetic noise—how the noise in different parts of the material and different moments in time change in concert with each other. Such magnetic noise correlations are difficult to measure directly, and they are often inferred from indirect measurements by measuring the scattering of particles off the material, which discards much of the information. This project will develop methods to directly measure magnetic noise correlations in materials using quantum sensors based on nitrogen vacancy (NV) centers in diamond, which will provide a new way to understand materials that can drive new technologies. In the context of this research program the PI will also pursue technology transfer to start-up and industry efforts, leveraging pre-existing relationships with industrial partners like Element Six. Synergisticall