Quantum-bath-driven decoherence of mixed spin systems

摘要: (Received 26 July 2013; revised manuscript received 19 December published 8 January 2014) Thedecoherenceofmixedelectron-nuclearspinqubitsisatopicofgreatcurrentimportance,butunderstanding is still lacking: While important decoherence mechanisms for spin qubits arise from quantum bath environments with slow decay of correlations, the only analytical framework explaining observed sharp variations times magnetic field based on suppression classical noise. Here we obtain a general expression central system which exposes significant differences between quantum-bath and by We perform measurements bismuth donors in natural silicon using both electron resonance (ESR) nuclear (NMR) transitions, cases find excellent agreement our theory across wide parameter range. The universality also tested quantitative comparisons previous around “optimal working points” or “clock transitions” where strongly suppressed. further validate results comparison to cluster expansion simulations.