I'm not really sure what your question is, but I'll try to answer it! To make a quantum computer, you need a number of qubits. If you want to use atoms as qubits, you need to be able to repeatably trap, hold, and interrogate them over "long" timescales. If you could only trap a single atom 50% of the time, your computer would be very inefficient if you have, say, 30 qubits (ie. an array of 30 single atoms). By pushing this up to 83%, efficiency improves dramatically. Also, they can probably do better than 83% by improving their vacuum, but this would require taking their apparatus apart somewhat, and is not something people tend to do once they have a working setup!