Angstrom-Scale Nuclear Magnetic Resonance Diffraction: A Route to Atomic Resolution Magnetic Resonance Imaging

Achieving atomic resolution is the ultimate limit of magnetic resonance imaging (MRI), and attaining this capability offers huge technological and scientific opportunities, from drug development to understanding the complex dynamics in interacting quantum systems. In this talk, I will present nuclear magnetic resonance diffraction (NMRd) – a new approach for achieving three-dimensional atomic resolution imaging of nuclear spins in crystalline solids. First proposed by Mansfield and Grannell1 , NMRd extends Fourier transform MRI to a periodic arrangement of spins to yield structure factor information with elemental specificity and atomic resolution, without the loss of phase information common to scattering techniques such as X-rays that detect the scattered field intensity. In this talk, I will present two recent results that utilize a force-detected nano-MRI apparatus to realize NMRd of P-spins in an InP nanowire. In the first experiment, we imprint a nanometer scale grating by periodically modulating the Z magnetization of P-spins, and detect the period and position of the grating with sub-Angstrom precision. In the second experiment, we vary the period of the grating from approximately 2 Å to 10 nm and study the transport of spin correlations under the dipolar interactions of the P-spins. We find that the transport in the Z magnetization is diffusive on lengthscales greater than about 2 nm and transitions to a ballistic transport regime below 2 nm. I will end the talk by describing upcoming work to extend the capabilities NMRd to image three-dimensional arrangement of spins in nanocrystalline solids