Magnetic field sensor using a Nitrogen Vacancy center in Diamond at Liquid Nitrogen TemperatureJoseph Lydon, Sagar BhandariDepartment of Physics and Engineering, Slippery Rock University, Slippery Rock, PA 16057*

We present our work on a magnetometer probe capable of measuring local change in magnetic field at liquid Nitrogen temperature. The magnetometer is based on Nitrogen Vacancy (NV) center in diamond. The negatively charged state of NV center in diamond consists of a nitrogen atom replacing the carbon atom next to a vacancy with spin state of 1. When irradiated by a 532 nm laser, the fluorescence of NV center is at 637 nm. The intensity of fluorescence depends on the spin state of the NV center before irradiation. The spin state of the NV center depends on the local magnetic field via Zeeman interaction. By using a proper sequence of laser and microwave pulses and measuring the fluorescence intensity, a highly sensitive magnetometer probe can be built. We report our progress and design of the magnetometer probe. The anticipated spatial resolution of the magnetometer is in the order of nanometers, with magnetic field resolution of nT.