Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 33: Quantum information: Concepts and methods II

Q 33.3: Talk

Tuesday, March 19, 2013, 14:30–14:45, E 214

Approximate Quantum Error Correction: optimal codes for independent and correlated errors — •Sol H. Jacobsen and Florian Mintert — Freiburg Institute for Advanced Studies, Albert-Ludwigs-University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany

The reversibility of open system dynamics in practice depends on a separation of probability regimes in which high-probability errors are corrected at the expense of leaving lower-probability errors uncorrected whenever these occur, i.e. correcting only errors on single qubits in a quantum code. However, several important quantum information processing scenarios are not describable by a neat separation of probability regimes, and we investigate codes for optimal information protection when this is the case. We use entanglement dynamics to compare and evaluate the performance of different codes and present optimal codes for full noisy quantum channels in terms of minimum deviation from perfect correctability. We present N-qubit inequalities governing optimal codes for different probability regimes of errors and give explicit examples of significant improvement for some standard cases.