FOB



Code: FOB Time Slot/Poster Number: 10:45-11:10 Session: Exotica & Beyond

Remotely Detected Magnetic Resonance Imaging and Velocimetry
Vikram Bajaj; Jeffrey Paulsen; Nicholas Halpern-Manners; Thomas Teisseyre; Elad Harel; Alexander Pines
LBNL & UC Berkeley, Berkeley, CA
Abstract
We present consequences and applications of a multidimensional magnetic resonance method, remotely detected MRI, in which sample flow or translation separates the encoding and detection steps of an experiment, allowing each to be separately optimized. The method is particularly useful in rapidly flowing samples, or in microporous or other materials in which low filling factors preclude sensitive direct imaging. We show acute examples within microfluidics, and preliminary applications in microporous systems, including the possibility of microimaging of vasculature in vivo. We discuss how remote detection will enable the operation of new portable magnetic resonance devices.

Code: FOB Time Slot/Poster Number: 11:10-11:25 Session: Exotica & Beyond

Multi-Slice Scanning Magnetic Imaging and Applications in Molecular Recognition
Shoujun Xu
University of Houston, Houston, TX
Abstract
We present a novel technique for direct imaging of magnetic nanoparticles. The technique, scanning magnetic imaging, is based on atomic magnetometry which utilizes optically-pumped atomic coherence interacting with polarized laser. In contrast to magnetic resonance imaging which relies on the relaxation contrast of nuclear spins to detect magnetic particles, our technique is capable of sensing dc magnetic signal. We show two applications in molecular imaging. One is quantitative binding of magnetically-labeled antibodies to specific targets. The other is measuring the rupture force of biotin-streptavidin interaction in a continuous flow mode. Finally, we compare scanning magnetic imaging with magnetic resonance imaging in terms of capability, sensitivity, and cost.

Code: FOB Time Slot/Poster Number: 11:25-11:50 Session: Exotica & Beyond

Compact Permanant Magnet NMR: On the path to portable NMR
Eiichi Fukushima1; Shin Utsuzawa2; Andrew McDowell1
1ABQMR, Albuquerque, NM; 2New Mexico Resonance, Albuquerque, New Mexico
Abstract
We present permanent magnet and probe combinations that advance the field of portable NMR. One is unilateral NMR that is functionally similar to NMR MOUSE but generates a remote uniform field spot that is well suited to characterize longer relaxation time signals. Another is a compact dipole magnet that yields NMR signals in 80 to 400 micron capillaries at 1 to 1.7T. The 1T magnet is 5cm cubed and weighs 700 grams. These magnets are used to detect magnetic nano-particles that perturb the static magnetic field for sufficient fractions of the cross-section to affect the signal. The same magnet in its unshimmed state has been used to obtain moderate resolution chemical shift spectra of ethanol.

Code: FOB Time Slot/Poster Number: 11:50-12:05 Session: Exotica & Beyond

Polarization transport in a one-dimensional spin chain
Chandrasekhar Ramanathan1; Paola Cappellaro1; Lorenza Viola2; David Cory1
1Massachusetts Institute of Technology, Cambridge, MA; 2Dartmouth College, Hanover, NH
Abstract
We characterize the spin dynamics underlying the transport of polarization in a spin chain under the nearest-neighbor-coupled isotropic XY and double quantum (DQ) Hamiltonians, in the weak polarization limit. We show that the spins evolves in a sub-space (N x N) of the system Hilbert space (n x n, where N = log2(n) ), and that the spin dynamics map on to a continuous-time quantum walk on a 1D graph. We experimentally measure the collective polarization of the spins under DQ evolution in a single-crystal of fluorapatite for both end-polarized and thermally polarized initial states. Excellent agreement is obtained between experiment and theory. This work opens the door to the experimental characterization of additional spin-spin correlations in these systems.

Code: FOB Time Slot/Poster Number: 12:05-12:30 Session: Exotica & Beyond

Electron Spin Actuator for Nuclear Spin Control
David Cory
MIT, Cambridge, MA
Abstract
Nuclear spins remain amongst the most promising quantum bits for quantum information processors and computers. Their long decoherence time, versatile chemistry and simple control make them well suited to storing quantum coherence. However, for many applications requiring processing the control of nuclear spins through RF fields and dipolar couplings is too slow for useful devices. We improve the speed of nuclear spin control by using an electron spin as a local actuator for the nuclear spins. Provided that the electron spin has resolved anisotropic hyperfine interactions with the nuclear spins, then we obtain universal coherent control over the nuclear spin Hilbert space while only modulating the electron spin. I will outline the theory and describe some experimental realizations.