Random-coupling spin-bath decoherence
= Random-coupling spin-bath decoherence
Independent random couplings suppress typical coherence as the bath size increases. This conclusion concerns an ensemble or a specified large-bath limit, and must be distinguished from a pointwise long-time limit for one finite realization. <Ensemble spin-bath coherence> supplies exact mean and mean-square formulas for a uniform coupling distribution, while <short-time Gaussian spin-bath decoherence> gives the initial decay scale.