An investigation of the antiferromagnet-based NMR quantum register in inhomogeneous magnetic field

It is given the refinements and further development of NMR model of quantum register based on easy-axis nuclear spin-free antiferromagnet, which was presented previously in paper. The model suggests that external magnetic field is directed along the easy axis, normally to the plate surface and has a weak constant gradient along the nuclear spin chain of quantum register. In present paper it is evaluated the general expression for indirect coupling between nuclear spins due to hyperfine nuclear-electron coupling in substituted atoms and spin-wave propagation in antiferromagnet close to critical point of quantum phase transition in antiferromagnet of spin-flop type. It is given also an estimation of quantum states decoherence rate, which is caused by the interaction of nuclear spins with spin waves in antiferromagnet.