Model of qubits as devices to detect the third moment of current fluctuations

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© 2006 American Physical Society (APS). http://www.aps.org/

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Journal Title

Journal ISSN

Volume Title

School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2006

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Mcode

Degree programme

Language

en

Pages

024524/1-9

Series

Physical Review B, Volume 74, Issue 2

Abstract

Under appropriate conditions, controllable two-level systems can be used to detect the third moment of current fluctuations. We derive a master equation for a quantum system coupled to a bath valid to the third order in the coupling between the system and the environment. In this approximation the reduced dynamics of the quantum system depends on the frequency-dependent third moment. Specializing to the case of a controllable two-level system (a qubit) and in the limit in which the splitting between the levels is much smaller than the characteristic frequency of the third moment, it is possible to show that the decay of the qubit has additional oscillations whose amplitude is directly proportional to the value of the third moment. We discuss an experimental setup where this effect can be seen.

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Keywords

current fluctuations, quantum system

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Citation

Brosco, Valentina & Fazio, Rosario & Hekking, F. W. J. & Pekola, Jukka. 2006. Model of qubits as devices to detect the third moment of current fluctuations. Physical Review B. Volume 74, Issue 2. 024524/1-9. ISSN 1098-0121 (printed). DOI: 10.1103/physrevb.74.024524.