PRX Quantum (Oct 2023)
How to Wire a 1000-Qubit Trapped-Ion Quantum Computer
Abstract
One of the most formidable challenges of scaling up quantum computers is that of control-signal delivery. Today’s small-scale quantum computers typically connect each qubit to one or more separate external signal sources. This approach is not scalable due to the input/output (I/O) limitations of the qubit chip, necessitating the integration of control electronics. However, it is no small feat to shrink control electronics into a small package that is compatible with qubit-chip fabrication and operational constraints without sacrificing performance. This so-called “wiring challenge” is likely to impact the development of more powerful quantum computers even in the near term. In this paper, we address the wiring challenge of trapped-ion quantum computers. We describe a control architecture called WISE (Wiring using Integrated Switching Electronics), which significantly reduces the I/O requirements of ion-trap quantum computing chips without compromising performance. Our method relies on judiciously integrating simple switching electronics into the ion-trap chip—in a way that is compatible with its fabrication and operation constraints—while the complex electronics remain external. To demonstrate its power, we describe how the WISE architecture can be used to operate a fully connected 1000-qubit trapped-ion quantum computer using approximately 200 signal sources at a speed of approximately 40–2600 quantum gate layers per second.