Quantum trajectories for the realistic measurement of a solid-state charge qubit

Oxtoby, N. P., Warszawski, P., Wiseman, H. M., Sun, H. B. and Polkinghorne, R. E.S. (2005) Quantum trajectories for the realistic measurement of a solid-state charge qubit. Physical Review B, Condensed matter and materials physics, 71 16: 1-9. doi:10.1103/PhysRevB.71.165317

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Author Oxtoby, N. P.
Warszawski, P.
Wiseman, H. M.
Sun, H. B.
Polkinghorne, R. E.S.
Title Quantum trajectories for the realistic measurement of a solid-state charge qubit
Journal name Physical Review B, Condensed matter and materials physics   Check publisher's open access policy
ISSN 1098-0121
Publication date 2005-01-01
Sub-type Article (original research)
DOI 10.1103/PhysRevB.71.165317
Open Access Status File (Publisher version)
Volume 71
Issue 16
Start page 1
End page 9
Total pages 9
Place of publication New York
Publisher American Physical Society
Language eng
Subject C1
240300 Atomic and Molecular Physics; Nuclear and Particle Physics; Plasma Physics
780102 Physical sciences
0299 Other Physical Sciences
Abstract We present a new model for the continuous measurement of a coupled quantum dot charge qubit. We model the effects of a realistic measurement, namely adding noise to, and filtering, the current through the detector. This is achieved by embedding the detector in an equivalent circuit for measurement. Our aim is to describe the evolution of the qubit state conditioned on the macroscopic output of the external circuit. We achieve this by generalizing a recently developed quantum trajectory theory for realistic photodetectors [P. Warszawski, H. M. Wiseman, and H. Mabuchi, Phys. Rev. A 65, 023802 (2002)] to treat solid-state detectors. This yields stochastic equations whose (numerical) solutions are the realistic quantum trajectories of the conditioned qubit state. We derive our general theory in the context of a low transparency quantum point contact. Areas of application for our theory and its relation to previous work are discussed.
Keyword Physics, Condensed Matter
Single-electron Transistor
Small Tunnel-junctions
Coulomb Blockade
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
2006 Higher Education Research Data Collection
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Citation counts: TR Web of Science Citation Count  Cited 22 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 23 times in Scopus Article | Citations
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Created: Wed, 15 Aug 2007, 15:28:11 EST