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arXiv · 0910.5052

Backaction of a charge detector on a double quantum dot

Shi-Hua Ouyang·Chi-Hang Lam·J. Q. You
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Abstract

We develop a master equation approach to study the backaction of quantum point contact (QPC) on a double quantum dot (DQD) at zero bias voltage. We reveal why electrons can pass through the zero-bias DQD only when the bias voltage across the QPC exceeds a threshold value determined by the eigenstate energy difference of the DQD. This derived excitation condition agrees well with experiments on QPC-induced inelastic electron tunneling through a DQD [S. Gustavsson et al., Phys. Rev. Lett. 99, 206804(2007)]. Moreover, we propose a new scheme to generate a pure spin current by the QPC in the absence of a charge current.

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Shi-Hua Ouyang, Chi-Hang Lam, J. Q. You. 2010-02-13. Backaction of a charge detector on a double quantum dot. https://doi.org/10.1103/physrevb.81.075301

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