arXiv:cond-mat/0002279 · Physical review. B, Condensed matter

Quantum measurement of coherent tunneling between quantum dots

Howard M. Wiseman, Dian Wahyu Utami, He Bi Sun, Gerard J Milburn, Bruce E. Kane, Andrew S. Dzurak, Robert G. Clark

Published May 21, 2001• 28 citations

Abstract

We describe the conditional and unconditional dynamics of two coupled quantum dots when one dot is subjected to a measurement of its occupation number by coupling it to a third readout dot via the Coulomb interaction. The readout dot is coupled to source and drain leads under weak bias, and a tunnel current flows through a single bound state when energetically allowed. The occupation of the quantum dot near the readout dot shifts the bound state of the readout dot from a low conducting state to a high conducting state. The measurement is made by continuously monitoring the tunnel current through the readout dot. We show that there is a difference between the time scale for the measurement-induced decoherence between the localized states of the dots, and the time scale on which the system becomes localized due to the measurement.

DOI: 10.1103/physrevb.63.235308

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