Reformulating the NMR Quantum Mechanics Fundamental Aspects: Spin 1/2 Evolution in Magnetic Field Gradients

Abstract

Magnetization of a spin1/2 set is determined by means of their individual wave function. The theoretical treatment based on the fundamental axioms of quantum mechanics and solving explicitly Schr\"odinger equation gives the evolution of spin1/2 system driven by magnetic fields. In this work we consider the energy of the spin system interacting with magnetic fields and all the other parts of the energy as a constant reservoir. Solving this complete Hamiltonian can explain the measured sign change of nuclear spin noise spectra compared to conventional NMR experiments and the possibility to make NMR images without radio frequency magnetic fields. The possibility to make NMR images without RF magnetic fields is an indication that entangled spin1/2 states can be manipulated by magnetic field gradients, opening a new way to perform quantum computation by NMR.