A Modernized View of Coherence Pathways in Magnetic Resonance Spectroscopy

Most Magnetic Resonance Experiments involve the acquisition of very large datasets consisting of complex data. Since relatively complicated Nuclear Magnetic Resonance (NMR) experiments date back decades, the traditional approach to this data was to dramatically reduce the amount of data at the accumulation stage. In particular, cycling the phase of excitation pulses allows one to isolate signal that arises from particular coherence pathways (i.e. signal that pulses move between particular elements of the density matrix following a particular pattern/pathway), and methods were developed to accumulate the data in a way that isolates the data from a particular pathway while discarding data from undesired pathways.

However, these techniques only work under idealized circumstances, and, especially in new and challenging situations that explore new physics, a new approach was required. Recently, we demonstrated a technique that can present all the data acquired during a Magnetic Resonance experiment in a meaningful fashion. It draws on modern open-source libraries in order to organize the data into a conveniently accessible multi-dimensional format and to present the resulting complex data using the domain coloring technique. We demonstrate the utility of this technique both for processing and optimizing data, as well as for diagnosing experimental non-idealities, and apply it to NMR and NMR-ESR dual-resonance techniques that our lab is pursuing.