Experiments with Nitrogen-Vacancy (NV) color centers
applying quantum metrology to condensed matter and many-body physics
In recent years, quantum defects in diamond known as nitrogen vacancy (NV) color centers have attracted intense interest as precision quantum sensors with wide-ranging applications in both the physical and life sciences. This defect is formed by a nitrogen impurity next to a missing carbon, or vacancy, in the diamond lattice, and can be created naturally or by nitrogen ion implantation and annealing. The electrons occupying the dangling bonds around the vacancy play the role of the electrons bound to the nucleus of an atom or ion, exhibiting long-lived spin states and well-defined optical transitions. Despite the fact that the NV center is surrounded by carbon atoms only angstroms away, its states are so well isolated from environmental perturbations that their coherence properties can be comparable to those of an ion trapped in ultra-high vacuum, with the spin coherence lifetime reaching 1 ms.
We are exploring how to use NV centers as nanoscale sensors that can perform magnetic imaging of molecules and materials at nanometer length scales: a "nanoscale MRI machine". We apply a broad array of techniques developed in quantum information science to enhance the sensitivity, and temporal and spatial resolution of these sensors, and use them to address key problems in condensed matter and many-body physics.
Some of the laboratory techniques and concepts we use are: lasers, confocal microscopy, radiofrequency and microwave engineering, photolithography, chemistry, magnetic resonance, and quantum information science.