Applying voltage to an array of electrodes on a chip

 The ions themselves are held in place by applying voltage to an array of electrodes on a chip. “If I do that correctly, then I can create an electromagnetic field that can hold on to a trapped ion just above the surface of the chip.” By changing the voltages applied to the electrodes, Chiaverini can move the ions across the surface of the chip, allowing for multiqubit operations between separately trapped ions.

So, while the qubits themselves are simple, fine-tuning the system that surrounds them is an immense challenge. “You need to engineer the control systems — things like lasers, voltages, and radio frequency signals. Getting them all into a chip that also traps the ions is what we think is a key enabler.”

Chiaverini notes that the engineering challenges facing trapped ion quantum computers generally relate to difference between computer science and computer engineering control rather than preventing decoherence; the reverse is true for superconducting-based quantum computers. And of course, there are myriad other physical systems under investigation for their feasibility as quantum computers.