Kousik Chandra,
"Noise Detected NMR Spectroscopy"
, in JOURNAL OF THE INDIAN INSTITUTE OF SCIENCE, Vol. 94, Nummer 4, INDIAN INST SCIENCE, INDIAN INST SCIENCE, BANGALORE 560012, INDIA, Seite(n) 517-526, 2014, ISSN: 0970-4140
Original Titel:
Noise Detected NMR Spectroscopy
Sprache des Titels:
Englisch
Original Kurzfassung:
Spin noise phenomenon was predicted way back in 1946. However,
experimental investigations regarding spin noise became possible only
recently with major technological improvements in NMR hardware. These
experiments have several potential novel applications and also demand
refinements in the existing theoretical framework to explain the
phenomenon. Elegance of noise spectroscopy in gathering information
about the properties of a system lies in the fact that it does not
require external perturbation, and the system remains in thermal
equilibrium. Spin noise is intrinsic magnetic fluctuations, and both
longitudinal and transverse components have been detected independently
in many systems. Detection of fluctuating longitudinal magnetization
leads to field of Magnetic Resonance Force Microscopy (MRFM) that can
efficiently probe very few spins even down to the level of single spin
utilizing ultrasensitive cantilevers. Transverse component of spin
noise, which can simultaneously monitor different resonances over a
given frequency range enabling one to distinguish between different
chemical environments, has also received considerable attention, and
found many novel applications. These experiments demand a detailed
understanding of the underlying spin noise phenomenon in order to
perform perturbation-free magnetic resonance and widen the highly
promising application area. Detailed investigations of noise
magnetization have been performed recently using force microscopy on
equilibrium ensemble of paramagnetic alkali atoms. It was observed that
random fluctuations generate spontaneous spin coherences which has
similar characteristics as generated by macroscopic magnetization of
polarized ensemble in terms of precession and relaxation properties.
Several other intrinsic properties like g-factors, isotope-abundance
ratios, hyperfine splitting, spin coherence lifetimes e
Forschungs-