Spin Chaos in Magnetic Resonance

摘要

The joint action of two readily observed effects in solution magnetic resonance―radiation damping and the dipolar field―are shown to generate spatiotemporal chaos in routine experiments. The extreme sensitivity of the chaotic spin dynamics to experimental conditions during the initial evolution period can be used to construct a spin amplifier to enhance sensitivity and contrast in magnetic resonance spectroscopy and imaging. Alternatively, amplification of intrinsic spin noise or tiny experimental perturbations such as temperature gradient fluctuations leads to signal interferences and highly irreproducible measurements. Controlling the underlying chaotic evolution provides the crucial link between amplifying weak signals and counteracting unwanted signal fluctuations.