On Protected Realizations of Quantum Information

Abstract

There are two complementary approaches to realizing quantum information so that it is protected from a given set of error operators. Both involve encoding information by means of subsystems. One is initialization-based error protection, which involves a quantum operation that is applied before error events occur. The other is operator quantum error correction, which uses a recovery operation applied after the errors. Together, the two approaches make it clear how quantum information can be stored at all stages of a process involving alternating error and quantum operations. In particular, there is always a subsystem that faithfully represents the desired quantum information. We give a definition of faithful realization of quantum information and show that it always involves subsystems. This justifies the "subsystems principle" for realizing quantum information. In the presence of errors, one can make use of noiseless, (initialization) protectable, or error-correcting subsystems. We give an explicit algorithm for finding optimal noiseless subsystems. Finding optimal protectable or error-correcting subsystems is in general difficult. Verifying that a subsystem is error-correcting involves only linear algebra. We discuss the verification problem for protectable subsystems and reduce it to a simpler version of the problem of finding error-detecting codes.

17 pages

References in corpus (9)

• On the Power of One Bit of Quantum Information
• A Theory of Quantum Error-Correcting Codes
• Quantum computation with optical coherent states
• Theory of Decoherence-Free Fault-Tolerant Universal Quantum Computation
• Stabilizer Formalism for Operator Quantum Error Correction
• A Unified and Generalized Approach to Quantum Error Correction
• Stabilizing Quantum Information
• Theory of Initialization-Free Decoherence-Free Subspaces and Subsystems
• Constructing Qubits in Physical Systems

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