Rona Ramos

The Intrinsic Origin of Spin Echoes in Dipolar Solids Generated by Strong Pulses

In spectroscopy, it is conventional to treat pulses much stronger than the linewidth as delta functions. In NMR, this assumption leads to the prediction that

Generating Unexpected Spin Echoes in Dipolar Solids with π Pulses

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Controlling coherence using the internal structure of hard pi pulses.

pulses do not refocus the dipolar coupling. However, NMR spin echo measurements in dipolar solids defy these conventional expectations when more than one

System and Methods for Manipulating Coherence of Spins and Pseudospins Using the Internal Structure of Strong Control Pulses

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Generating Novel Spin Echoes Using the Internal Structure of Strong Pi-Pulses

pulse is used. Observed effects include a long tail in the CPMG echo train for short delays between

A New Approach to Spin Coherence Control: Extreme Line-narrowing and MRI of Solids

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Generating Spin Echoes with Pi-Pulses: More is Different

pulses, an even-odd asymmetry in the echo amplitudes for long delays, an unusual fingerprint pattern for intermediate delays, and a strong sensitivity to

Visualizing and Manipulating the Density Matrix to Understand Multiple Pulse NMR

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New Spin Echo Phenomena Arising from Strong Pi-Pulses

-pulse phase. Experiments that set limits on possible extrinsic causes for the phenomena are reported. We find that the action of the systems internal Hamiltonian during any real pulse is sufficient to cause the effects. Exact numerical calculations, combined with average Hamiltonian theory, identify terms that are sensitive to parameters such as pulse phase, dipolar coupling, and system size. Visualization of the entire density matrix shows a unique flow of quantum coherence from nonobservable to observable channels when applying repeated

Observation of Anomolously Long-Lived Spin Echoes in a Dense Dipolar Spin System

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