Universal quantum computation in decoherence-free subspaces with hot trapped-ions

Leandro Aolita, Luiz Davidovich, Kihwan Kim, Hartmut Häffner

Published 2007-06-01Version 1

We consider interactions that generate a universal set of quantum gates on logical qubits encoded in a collective-dephasing-free subspace, and discuss their implementations with trapped ions. This allows for the removal of the by-far largest source of decoherence in current trapped-ion experiments, collective dephasing. In addition, an explicit parametrization of all two-body Hamiltonians able to generate such gates without the system's state ever exiting the protected subspace is provided.