A model for measurement of the states in a coupled-dot qubit

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Title A model for measurement of the states in a coupled-dot qubit
Author Sun, He-Bi; Wiseman, Howard Mark
Journal Name Journal of Physics: Condensed Matter
Year Published 2009
Place of publication United Kingdom
Publisher Institute of Physics Publishing
Abstract We propose a quantum trajectory analysis of a scheme to measure the states of a coupled-dot device (qubit) where there is a fluctuating energy gap Δ between the two states. The system consists of the qubit and a readout dot coupled to source and drain leads. The tunnel rate through the detector is conditioned by the occupation number of the nearer quantum dot (target) of the qubit and therefore probes the states of the qubit. We derive a Lindblad-form master equation to calculate the unconditional evolution of the qubit and a conditional stochastic master equation calculating the conditional evolution for different tunneling rates. The results show the effects of various device parameters and provide the optimum selection and combination of the system structure.
Peer Reviewed Yes
Published Yes
Alternative URI http://dx.doi.org/10.1088/0953-8984/21/12/125301
Copyright Statement Copyright 2009 Institute of Physics Publishing. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher.Please refer to the journal's website for access to the definitive, published version.
Volume 21
Page from 125301-1
Page to 125301-5
ISSN 0953-8984
Date Accessioned 2009-07-20
Language en_AU
Research Centre Centre for Quantum Dynamics
Faculty Faculty of Science, Environment, Engineering and Technology
Subject Quantum Information, Computation and Communication
URI http://hdl.handle.net/10072/26024
Publication Type Journal Articles (Refereed Article)
Publication Type Code c1

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