English

Parity meter for charge qubits: an efficient quantum entangler

Mesoscale and Nanoscale Physics 2007-05-23 v2 Quantum Physics

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.

Keywords

Cite

@article{arxiv.cond-mat/0602514,
  title  = {Parity meter for charge qubits: an efficient quantum entangler},
  author = {B. Trauzettel and A. N. Jordan and C. W. J. Beenakker and M. Buttiker},
  journal= {arXiv preprint arXiv:cond-mat/0602514},
  year   = {2007}
}

Comments

8 pages, 4 figures; v2: discussion of measurement time, references added