Recursive encoding and decoding of the noiseless subsystem and decoherence-free subspace

Chi Kwong Li, Mikio Nakahara, Yiu Tung Poon, Nung Sing Sze, Hiroyuki Tomita

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)


When an environmental disturbance to a quantum system has a wavelength much larger than the system size, all qubits in the system are under the action of the same error operator. The noiseless subsystem and decoherence-free subspace are immune to such collective noise. We construct simple quantum circuits that implement these error-avoiding codes for a small number n of physical qubits. A single logical qubit is encoded with n=3 and 4, while two and three logical qubits are encoded with n=5 and 7, respectively. Recursive relations among subspaces employed in these codes play essential roles in our implementation.
Original languageEnglish
Article number044301
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number4
Publication statusPublished - 5 Oct 2011

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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