1203.5607 (S. J. Balian et al.)

Suppression of decoherence due to spin diffusion for bismuth qubits in
silicon    [PDF]

S. J. Balian, M. B. A. Kunze, M. H. Mohammady, G. W. Morley, W. M. Witzel, C. W. M. Kay, T. S. Monteiro

We present pulsed electron-nuclear double resonance experiments which enable us to quantify and characterize, for the first time, the coupling between bismuth donor spin qubits and the surrounding $^{29}\text{Si}$ impurities; the latter provide the dominant decoherence mechanism (nuclear spin diffusion) in this system. Cluster expansion simulations show near-complete suppression of spin diffusion at optimal working points. The suppression takes the form of sharply peaked divergences of the spin diffusion time $T_{\text{SD}}$, in contrast with previously identified broader regions of insensitivity to classical fluctuations.

View original: http://arxiv.org/abs/1203.5607