Direct Characterization of Quantum Dynamics with Noisy Ancilla

Abstract

We present methods for the direct characterization of quantum dynamics (DCQD) in which both the principal and ancilla systems undergo noisy processes. Using a concatenated error detection code, we discriminate between located and unlocated errors on the principal system in what amounts to filtering of ancilla noise. The example of composite noise involving amplitude damping and depolarizing channels is used to demonstrate the method, while we find the rate of noise filtering is more generally dependent on code distance. Our results indicate the accuracy of quantum process characterization can be greatly improved while remaining within reach of current experimental capabilities.

7 pages, 4 figures

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Cited by in corpus (5)

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• Near-Hashing-Bound Multiple-Rate Quantum Turbo Short-Block Codes
• Estimation of coherent error sources from stabilizer measurements
• Discrimination of correlated and entangling quantum channels with selective process tomography
• The two-qubit amplitude damping channel: characterization using quantum stabilizer codes