November_EDFA_Digital

edfas.org ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 22 NO. 4 50 GUEST COLUMNIST QUANTUM COMPUTING IS STILL IN BASIC RESEARCH PHASE Paul Teich, Liftr Insights Paul.Teich@LiftrInsights.com C ommercially viable, practical general-purpose quantum computing is still at least 15 years away. That is not a popular opinion, but it is grounded in economic return on investment (ROI) reality. The current level of interest and investment in quantum computing is due to the impending death of Moore’s Law. Readers of EDFA Magazine may quibble that certain aspects of Moore’s Laware still alive or at least still twitching. But the semiconductormanufacturing industry is in the endgame for the first corollary to Moore’s Law, which states “your next fab will be twice as expensive as the last.” Thereareonly a small handful of fabs leftonEarth capable of funding both the research and manufacturing buildout to reach 5 nm and below. The challenge for our industry is that there are few viable alternatives to CMOS. There are other materials approaches, such as graphene, but they are decades behind CMOS in terms of process maturity and scaling capability. Quantumcomputing is the only demonstrable alterna- tive to CMOS that is fundamentally different from current semiconductor approaches. Our industry’s hope is that quantumcomputing can leapfrog other approaches, both in speed of innovation and for continuing to accelerate compute capabilities. The state of general-purpose quantum computing today is simple: there are no best practices, because there is no agreement on or even demonstrations of functional, scalable general-purposequantumcomputing. Plus, there is abewilderingandexpandingarrayof emerging technical approaches to quantum computing. However, underneath that research complexity lie a few areas where research and innovation can be lever- aged across architectures. I’ll set aside optical quantum computing solutions, which have a unique set of scaling challenges, as well as quantum annealing architectures. And for amoment I’ll also ignore the plethora of emerging qubit technologies. The shared near-term challenges for quantum com- puting can be summarized as isolation and detection as described below. Physical isolation : We already understand this quite well in support of current fabrication technologies. Thermal isolation : Qubits, the computational ele- ments of quantum computers, must be very still, so physical isolation is not enough. Current state-of-the-art is to chill qubits to 15-20 milli-Kelvins using diffusion refrigeration technologies. Cryogenic electronics : Operating modern semi- conductor-based control systems at deep sub-Kelvin temperatures is poorly characterized. For example, Intel recently announced its “Horse Ridge” cryogenic control chip as a first step toward developing commercially viable control systems that can function in the extreme cold of a quantum computer. Also, transmitting and receiving control data from normal data center temperatures to sub-Kelvin temperatures presents challenges for both CMOS and optical designs. Sensor integration : Each quantum computing architecture has unique sensor requirements. However, standardizing sensor interfaces so that control systems might be standardized shouldbe apriority across research teams. That is Intel’smotivation behind developing Horse Ridge. Electromagnetic isolation : Qubits and their sensors must be isolated from each other and from the macro universe. This isolationmust be sufficient to enable qubits “IN THE MIDST OF CHAOS, THERE IS ALSO OPPORTUNITY.” —SUN TZU, THE ART OF WAR