23 May 2005 Simple quadrature-based quantum feedback of a solid-state qubit (Invited Paper)
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Proceedings Volume 5846, Noise and Information in Nanoelectronics, Sensors, and Standards III; (2005) https://doi.org/10.1117/12.609280
Event: SPIE Third International Symposium on Fluctuations and Noise, 2005, Austin, Texas, United States
Abstract
We analyze the newly proposed quantum feedback loop for a solid-state qubit, based on monitoring the quadrature components of the current from a weakly coupled detector, which continuously measures the qubit. Similar to the earlier proposal of the "Bayesian" feedback, the feedback loop is used to maintain the coherent (Rabi)oscillations in a qubit for an arbitrarily long time; however, this is done in a significantly simpler way, which requires much smaller bandwidth of the control circuitry. The price for simplicity is a less-than-ideal operation: the fidelity is limited to about 95%. The feedback loop operation can be experimentally verified by appearance of a positive in-phase component of the detector current relative to an external oscillating signal used for synchronization. The quadrature-based quantum feedback seems to be within the reach of the present-day technology.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alexander N. Korotkov, Alexander N. Korotkov, } "Simple quadrature-based quantum feedback of a solid-state qubit (Invited Paper)", Proc. SPIE 5846, Noise and Information in Nanoelectronics, Sensors, and Standards III, (23 May 2005); doi: 10.1117/12.609280; https://doi.org/10.1117/12.609280
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