Equilibrium Noise Suppression by Modulating Contact TransparencyY. B. Sherkunov, Jin Zhang, N. d'Ambrumenil, B. Muzykantskii

Department of Physics, University of Warwick, Coventry, CV4 7AL, U.K.

ABSTRACTControlled injection of single electrons into a ballistic conductor is essential for ``moving-electron-based'' quantum computation. We obtain the full counting statistics (FCS) of a quantum point contact (QPC) for the case when the contact transparency is modulated in time, which is shown to be equivalent to a system with a time-dependent bias voltage applied between the leads. We demonstrate two optimal contact opening schemes with the equilibrium noise largely suppressed. The potential applications includes an optimal electronic entangler and on-demand single electron source.

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References:Ivanov, Lee, Levitov, Phys. Rev. B 56, 6839 (1997)Keeling, Klich, Levitov, Phys. Rev. Lett. 97, 116403 (2006)Abanov and Ivanov, Phys. Rev. Lett. 100, 086602 (2008)YS, JZ, NdA, BM, arXiv:0812.4433v3JZ, YS, NdA, BM, in preparation

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