  A universal set of quantum gates is constructed for the recently developed
jump-error correcting quantum codes. These quantum codes are capable of
correcting errors arising from the spontaneous decay of distinguishable qubits
into statistically independent reservoirs. The proposed universal quantum gates
are constructed with the help of Heisenberg- and Ising-type Hamiltonians acting
on these physical qubits. This way it is guaranteed that the relevant error
correcting code space is not left at any time even during the application of
one of these quantum gates. The proposed entanglement gate is particularly well
suited for scalable quantum processing units whose elementary registers are
based on four-qubit systems.
