The Moyal representation for spin

Behind Quantum Electronics: National Security as Basis for Physical Research in the United States, 1940-1960

https://iopscience.iop.org/article/10.1088/1674-1056/27/2/020308/pdf

Nuclear magnetic resonance for quantum computing: Techniques and recent achievements

We want to review the applications of high-frequency-flippers in neutron spin echo and related fields: Two separated flippers of this type can replace a homogenous static magnetic field in a spin-echo spectrometer. We describe the spin-echo instruments at Saclay and Berlin relying on such flippers and present some measurements. By tilting these coils with respect to the beam axis, one can determine line widths of phonons with unprecedented precision. First experiments are shown. With two flippers driven at different frequencies one can realise an instrument (“MIEZE”), where the intensity at the detector is modulated with a frequency up to several MHz. Its use for high-resolution quasielastic scattering from protonated samples is demonstrated. The high-frequency signal may be used for “neutron computer holography” – we discuss a possible realisation.

Prospects of resonance spin echo

Single-scan multidimensional NMR

Nuclear magnetic resonance in bulk matter was discovered independently by Purcell, Torrey, and Pound at Harvard and by Bloch, Hansen, and Packard at Stanford towards the end of 1945. Their experiments were so different that members of neither group were quick to recognize their own experiment in the other. The magnetic resonance phenomenon was conceptualized differently by the two groups, and the design of their experiments differed accordingly. The Purcell group thought of magnetic resonance in terms of transitions between quantum states while the Bloch group visualized magnetic moments being reoriented with respect to a magnetic field. The conceptual approach adopted by each group can be seen as a natural consequence of earlier influences.

https://www.lfns.it/STORIA/Scuola%202014/18%20febbraio/Giuliani/stato%20solido/rigden_on_rabi.pdf

John S. Rigden

Papers

Quantum states and precession: The two discoveries of NMR