Centralizer theory for long-lived spin states

Long-lived Nuclear Spin States in Multiple-Spin Systems

a ) 400 MHz 1H-NMR spectrum at 300 K of citric acid; b) typical singlet state pattern obtained for t = 1 ms; c) singlet state pattern obtained for t = 3.5 s. The sequence, originally written for the AX case, was applied to the citric acid, an AA’BB’ four spin system. The CW decoupling was set to 3.5 kHz while the timing optimized to obtain the maximum population of the singlet state at the time...

Hyperpolarized long-lived nuclear spin states in monodeuterated methyl groups.

Monodeuterated methyl groups may support a long-lived nuclear spin state, with a relaxation time exceeding the conventional spin-lattice relaxation time T1. Dissolution-DNP (dynamic nuclear polarization) may be used to hyperpolarize such a long-lived spin state. This is demonstrated for the CH2D groups of a piperidine derivative. The polarized sample is manipulated in the ambient magnetic field...

Long-lived nuclear spin states far from magnetic equivalence.

Clusters of coupled nuclear spins may form long-lived nuclear spin states, which interact weakly with the environment, compared to ordinary nuclear magnetization. All experimental demonstrations of long-lived states have so far involved spin systems which are close to the condition of magnetic equivalence, in which the network of spin-spin couplings is conserved under all pair exchanges of symm...

Long-Lived Spin Coherence States in Semiconductor Heterostructures

Long-lived nuclear spin states in the solution NMR of four-spin systems.

The existence of long-lived nuclear spin states in four-spin systems is explored by solution-state NMR experiments. Long-lived states are proved to exist in three different natural product molecules, each containing either a AA'BB' or a AA'XX' proton spin system. The measured state lifetimes are between four and eight times the spin-lattice relaxation time constants.