Prospects for NMR Spectral Prediction on Fault-Tolerant Quantum Computers

Nuclear magnetic resonance spectroscopy is a prominent analytical tool, with applications throughout chemistry, medicine and solid-state physics. While conventional NMR spectrometers require large magnetic fields to interrogate a sample, recent advances in atomic magnetometry have enabled this spectroscopy far below geomagnetic field strengths. This zero-to-ultralow (ZULF) field regime can be advantageous since it mitigates relaxation and reveals spin couplings that are otherwise obscured, all while using compact and lower-overhead instrumentation. The resulting spectra are nonetheless difficult to interpret without computation, which can be taxing due to the presence of vector couplings and long-range spin networks. Following recent proposals, we demonstrate how fault-tolerant quantum computation could be used to simulate these spectra. Our analysis spans from input selection to the construction of explicit circuits based on qubitized quantum dynamics. By maintaining parity with experimental requirements, we demonstrate how NMR spectral prediction might be an early application for fault-tolerant quantum computers.