Intel’s director of quantum hardware, Jim Clarke, explains the company’s two quantum computing technologies The limits of Tangle Lake’s technology Silicon spin qubits and how far away they are The importance of cryogenic control electronics Top quantum computing applications What problems keeps him up at night AI vs. Quantum Computing: which will be more important? IEEE Spectrum: What’s special about Tangle Lake? Jim Clarke:I can’t underscore, for these systems, how important the packaging is. Typically we make our computers to run at room temperature, in our back pocket or on our wrist or slightly higher temperatures, but never at a fraction of a degree above absolute zero [as you need for superconducting qubits]. So these guys developed a package that could withstand the temperatures mechanically and still be relatively clean from a signal perspective. IEEE Spectrum: Is there a limit to the density of qubits using thetechnology in Tangle Lake? Thosepinouts look pretty big. Clarke: I think already this is the largest chip-to-[printed circuit board] attachment that Intel has ever done. So any larger than this on a single piece—the coefficient of thermal expansion and shrinkage would be severe. Not only that, as you see, the actual connectors have a very large footprint, and those are important right now. We can go bigger (more qubits per chip) with this technology, but not by much. So, what we’ll do is work to make the qubits smaller andthe connections smaller. And so, within the same size footprint, we can maybe increase the number of qubits by several factors.But it’s hard to reach a place with that technology where you’d have the millions of qubits you would need to do something really life altering.