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Parity meter for charge qubits: an efficient quantum entangler

B. Trauzettel·A. N. Jordan·C. W. J. Beenakker·M. Buttiker
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Abstract

We propose a realization of a charge parity meter based on two double quantum dots alongside a quantum point contact. Such a device is a specific example of the general class of mesoscopic quadratic quantum measurement detectors previously investigated by Mao et al. [Phys. Rev. Lett. 93, 056803 (2004)]. Our setup accomplishes entangled state preparation by a current measurement alone, and allows the qubits to be effectively decoupled by pinching off the parity meter. Two applications of the parity meter are discussed: the measurement of Bell's inequality in charge qubits and the realization of a controlled NOT gate.

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B. Trauzettel, A. N. Jordan, C. W. J. Beenakker, M. Buttiker. 2006-04-26. Parity meter for charge qubits: an efficient quantum entangler. https://doi.org/10.1103/physrevb.73.235331

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