Effective noise channels for encoded quantum systems

Abstract

We investigate effective noise channels for encoded quantum systems with and without active error correction. Noise acting on physical qubits forming a logical qubit is thereby described as a logical noise channel acting on the logical qubits, which leads to a significant decrease of the effective system dimension. This provides us with a powerful tool to study entanglement features of encoded quantum systems. We demonstrate this framework by calculating lower bounds on the lifetime of distillable entanglement and the negativity for encoded multipartite qubit states with different encodings. At the same time, this approach leads to a simple understanding of the functioning of (concatenated) error correction codes.

10 pages, 6 figures

References in corpus (7)

• Scaling laws for the decay of multiqubit entanglement
• Degenerate Quantum Codes for Pauli Channels
• Stable macroscopic quantum superpositions
• New lower bounds on the non-zero capacity of Pauli Channels
• Stability of encoded macroscopic quantum superpositions
• Robust multipartite quantum correlations without complex encodings
• Graph state basis for Pauli Channels

Cited by in corpus (12)

• Open-System Dynamics of Entanglement
• Measurement-based Quantum Communication
• Errors and pseudo-thresholds for incoherent and coherent noise
• Multipartite state generation in quantum networks with optimal scaling
• Delocalized information in quantum networks
• Measurement based quantum communication with resource states generated by entanglement purification
• Construction of optimal resources for concatenated quantum protocols
• Robustness of the concatenated quantum error-correction protocol against noise for channels affected by fluctuation
• Generality of the concatenated five-qubit code
• Memory-corrected quantum repeaters with adaptive syndrome identification
• Immense Fidelity Enhancement of Encoded Quantum Bell Pairs at Short and Long-distance Communication along with Generalized Design of Circuit
• Feasible logic Bell-state analysis with linear optics