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

Abstract

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