Experimental noise filtering by quantum control
| Autor: | Soare, A., Ball, H., Hayes, D., Sastrawan, J., Jarratt, M. C., McLoughlin, J. J., Zhen, X., Green, T. J., Biercuk, M. J. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/nphys3115 |
| Popis: | Instabilities due to extrinsic interference are routinely faced in systems engineering, and a common solution is to rely on a broad class of $\textit{filtering}$ techniques in order to afford stability to intrinsically unstable systems. For instance, electronic systems are frequently designed to incorporate electrical filters composed of, $\textit{e.g.}$ RLC components, in order to suppress the effects of out-of-band fluctuations that interfere with desired performance. Quantum coherent systems are now moving to a level of complexity where challenges associated with realistic time-dependent noise are coming to the fore. Unfortunately, standard control solutions involving feedback are generally impossible due to the strictures of quantum mechanics, and existing error-suppressing gate constructions generally rely on unphysical bang-bang controls or quasi-static error models that do not reflect realistic laboratory environments. In this work we use the theory of quantum control engineering and experiments with trapped $^{171}$Yb$^{+}$ ions to demonstrate the construction of novel $\textit{noise filters}$ which are specifically designed to mitigate the effect of realistic time-dependent fluctuations on qubits \emph{during useful operations}. Starting with desired filter characteristics and the Walsh basis functions, we use a combination of analytic design rules and numeric search to construct time-domain noise filters tailored to a desired state transformation. Our results validate the generalized filter-transfer function framework for arbitrary quantum control operations, and demonstrate that it can be leveraged as an effective and efficient tool for developing novel robust control protocols. Comment: Related work available from http://www.physics.usyd.edu.au/~mbiercuk/Publications.html |
| Databáze: | arXiv |
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