121 research outputs found
High-Resolution Nanoscale Solid-State Nuclear Magnetic Resonance Spectroscopy
We present a new method for high-resolution nanoscale magnetic resonance
imaging (nano-MRI) that combines the high spin sensitivity of nanowire-based
magnetic resonance detection with high spectral resolution nuclear magnetic
resonance (NMR) spectroscopy. By applying NMR pulses designed using optimal
control theory, we demonstrate a factor of reduction of the proton spin
resonance linewidth in a volume of polystyrene and
image proton spins in one dimension with a spatial resolution below
.Comment: Main text: 8 pages, 6 figures; supplementary information: 10 pages,
10 figure
Nanomechanical detection of nuclear magnetic resonance using a silicon nanowire oscillator
We report the use of a silicon nanowire mechanical oscillator as a
low-temperature nuclear magnetic resonance force sensor to detect the
statistical polarization of 1H spins in polystyrene. Under operating
conditions, the nanowire experienced negligible surface-induced dissipation and
exhibited a nearly thermally-limited force noise of 1.9 aN^2/Hz in the
measurement quadrature. In order to couple the 1H spins to the nanowire
oscillator, we have developed a new magnetic resonance force detection protocol
which utilizes a nanoscale current-carrying wire to produce large
time-dependent magnetic field gradients as well as the rf magnetic field.Comment: 14 pages, 5 figure
Growth and Transport Properties of Complementary Germanium Nanowire Field Effect Transistors
n- and p-type Ge nanowires were synthesized by a multistep process in which axial elongation, via vapor–liquid–solid (VLS) growth, and doping were accomplished in separate chemical vapor deposition steps. Intrinsic, single-crystal, Ge nanowires prepared by Au nanocluster-mediated VLS growth were surface-doped in situ using diborane or phosphine, and then radial growth of an epitaxial Ge shell was used to cap the dopant layer. Field-effect transistors prepared from these Ge nanowires exhibited on currents and transconductances up to 850 µA/µm and 4.9 µA/V, respectively, with device yields of \u3e85%
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