Single-spin magnetic resonance spectroscopy and imaging

Magnetic resonance spectroscopy studies matter by probing the resonant frequencies and couplings of paramagnetic nuclei and unpaired electrons. It is a cornerstone of modern science, with numerous applications in condensed-matter physics, materials science, chemistry, biology, and medical imaging. A counterpart is low sensitivity. Conventional spectrometers need large numbers of identical objects to detect a signal. This is an issue for systems with inhomogeneous properties, since their ensemble linewidth is then larger than the linewidth of the individual objects, which limits spectral resolution. The vision of ONESPIN is to apply magnetic resonance spectroscopy to individual objects, based on a new method recently developed in my laboratory. We detect individual electronic paramagnetic centers at 10mK by counting the fluorescence microwave photon emitted when they relax radiatively to the ground state, using a single-microwave-photon detector based on a superconducting qubit. The first project objective is to apply this fluorescence detection method to a large variety of individual paramagnetic centers (organic radicals, transition-metal-ion-containing molecules, enzymes, catalytic centers), which will yield the first single-center-resolved spectra on these systems. The second objective is high-resolution spectroscopy and imaging of the nuclear spins surrounding an individual paramagnetic center by combining hyperfine spectroscopy with fluorescence detection. We will obtain the first magnetic resonance images of individual molecules with single-nuclear-spin resolution, a long-standing dream of magnetic resonance. The third objective is magnetic resonance imaging with 10nm resolution of individual paramagnetic centers in a micron-scale sample by combining magnetic gradients with fluorescence detectionWe will develop new methodologies for single electron- and nuclear-spin magnetic resonance spectroscopy, using microwave photon counting at millikelvin temperatures.