We collaborate with our good friend, Prof. Chris Laumann to explore the quantum sensing of correlated materials at high pressures. Pressure unlocks new physics. From record high temperature superconductivity to exotic low dimensional magnetism, compressing quantum materials lets us squeeze out fascinating novel phenomena. 

There’s a catch—pressure is force by area, so going to high pressures means using very small material samples. These thin micron-scale samples are compressed between two opposing diamonds, in a geometry known as the diamond anvil cell (DAC).  DACs, the most versatile approach to generating sustained high pressures inside the laboratory, are necessarily much larger than the samples they compress. This makes measuring material properties such as magnetism or strain tricky, owing to the large background of the DAC. As with ambient-pressure materials, we need some way to measure the nanoscale properties of these materials to make sense of the physics they exhibit. 

The nitrogen vacancy (NV) center provides an elegant solution. Among the myriad possibilities (see our other projects!) that these atom-like diamond defects enable, the NV center is an exceptional quantum sensor. Their extreme sensitivity and atomistic size make them perfectly suited for measuring quantum materials locally and precisely. By integrating NV centers directly into the diamonds comprising our DACs, we can address the magnetic, electrical, stress, and thermal properties of materials directly to comprehensively understand how pressure modifies their physics.

Currently, we’re interested in understanding the inner workings of hydride superconductors and pressure-driven quantum critical points, but the potential of the NV-DAC is vast and exciting!