Maryland today | Mapping the Quantum Frontier
But what if we removed the requirement that a quantum computer be as reliable as an ordinary computer? How about working up Everest by climbing hills first? Basically, that describes the RQS approach, said its director and principal investigator, Andrew Childs, a computer science professor who also co-directs the Joint Center for Quantum Information and Computinga UMD-NIST partnership.
When quantum computers were first proposed in the 1980s, the idea was to use them to understand quantum systems too complex for classical computers, Childs said.
“One approach is to build a large-scale, fault-tolerant quantum computer that you can program however you want to simulate quantum mechanics,” he said.
Since such computers do not yet exist, scientists in Maryland have paved the way with an already feasible alternative approach: analog quantum simulation. “In this case, instead of a digital computer that you can use for anything, you’re building a system that will replicate the characteristics of the quantum system you want to study,” he said. “Maybe it’s somewhat programmable in that you have knobs to turn to adjust settings, but it’s still a simulation of a system rather than offering the full flexibility of a fully digital computer.”
Kollár, who is focused on developing a new type of superconducting qubit, describes herself as “an analog hardware enthusiast at heart”.
“With a digital quantum computer, the goal is total control, and the qubit does exactly what you want,” she said. “A quantum simulator is much more about letting nature take its course and figuring out what it’s doing, but about trying to find an interesting course.”
Even a modest knob-twisting simulator, Childs points out, is still a quantum processor, even if that’s not what he envisions in his theoretical work on algorithms for ideal systems. “For now, it’s an accessible way to move forward…and at the same time understand some of the general issues.”