Researchers at Leibniz University Hannover (LUH) and Physikalisch-Technische Bundesanstalt (PTB) have now developed a new method for ion-trapped qubits under vacuum by using electric fields above a chip structure.
Qubit operations are implemented by sending microwave signals through special conductor loops embedded in the chip structure. Usually, logic operations are carried out via extremely carefully controlled laser beams. Using microwave fields has the advantage that they are both relatively easy to control and a highly mature technology.
The team succeeded in demonstrating that specifically shaped microwave pulses, where the field is turned on and off smoothly, produce error rates 100 times lower than those where the fields are simply switched on and off—with the same energy input and despite the presence of noise. (Leibniz Universität Hannover)