Decoherence-free quantum information in the presence of dynamical evolution

Abstract

We analyze decoherence-free (DF) quantum information in the presence of an arbitrary non-nearest-neighbor bath-induced system Hamiltonian using a Markovian master equation. We show that the most appropriate encoding for N qubits is probably contained within the ~(2/9) N excitation subspace. We give a timescale over which one would expect to apply other methods to correct for the system Hamiltonian. In order to remain applicable to experiment, we then focus on small systems, and present examples of DF quantum information for three and four qubits. We give an encoding for four qubits that, while quantum information remains in the two-excitation subspace, protects against an arbitrary bath-induced system Hamiltonian. Although our results are general to any system of qubits that satisfies our assumptions, throughout the paper we use dipole-coupled qubits as an example physical system.

8 pages, 4 figures

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Cited by in corpus (5)

• Symmetries and conserved quantities in Lindblad master equations
• Non-stationary coherent quantum many-body dynamics through dissipation
• Adiabatic Control of Decoherence-Free-Subspaces in an Open Collective System
• Decoherence-free quantum information in Markovian systems
• Mean first-passage time of quantum transition processes