Direct 3D Imaging of Molecular Structure: Quantum Sensing and Control

University Of Washington, Seattle WA

Investigators

Abstract

0097544 Garbini One of the oldest and most enduring dreams of the scientific community is to directly observe molecular structure nondestructively, in situ, in three dimensions, with Angstrom-scale resolution. Such an imaging technology would immediately address urgent needs in nanoscale engineering, materials science, molecular biology, and medicine. The objective of the proposed research is to create such a technology. The proposed method is magnetic resonance force microscopy MRFM, which was conceived in 1991, by the proposers specifically as a means for 3D molecular imaging. The central concept of MRFM is to combine three-dimensional magnetic resonance imaging with angstrom-scale probe microscopy. MRFM was first experimentally demonstrated in 1992 in collaboration with Dan Rugar's IBM group. Subsequently, MRFM has developed into a worldwide sensing and imaging research effort. The specific aims of this NSF proposal are to: (1) demonstrate nanoscale resolution in 3D MRFM imaging; (2) achieve a reliable, experimentally validated understanding of electron and proton spin relaxation in the MRFM environment; and (3) extend present design principles for optimal control and estimation to the quantum environment appropriate to single spin imaging. The proposed means are to: (1) validate and calibrate the proposers' newly completed 3D MRFM scanner, via force, parametric, and multiplex imaging experiments; (2) design and operate a next-generation adaptive digital controller, incorporating optimal control, estimation, and diagnostic algorithms; and (3) survey electron and proton spin relaxation in a variety of target samples. The proposed opening of a new imaging window onto the largely unobserved world of 3D molecular structure will revolutionize the fields of nanoscale engineering, materials science, biology, medicine, and engineering education.