  This paper discusses ways to implement two-qubit gate operations for quantum
computing with cold trapped ions within one step. The proposed scheme is widely
robust against parameter fluctuations and its simplicity might help to increase
the number of qubits in present experiments. Basic idea is to use the quantum
Zeno effect originating from continuous measurements on a common vibrational
mode to realise gate operations with very high fidelities. The gate success
rate can, in principle, be arbitrary high but operation times comparable to
other schemes can only be obtained by accepting success rates below 80%.
