Researchers on two continents are reporting two big breakthroughs in quantum computing today — a quantum system built on the familiar von Neumann processor-memory architecture, and a working digital quantum simulator built on a quantum-computer platform. Although these developments are still constrained to the lab, they’re yet another sign that a quantum leap in computing may be just around the corner.

In the first study, researchers at the University of California-Santa Barbara say they’ve built the first working quantum computer chip based on the von Neumann system. Named for the engineer who designed the concept, the von Neumann architecture combines processors and memory, and it’s the basis for every computer out there. (With one notable recent exception.)

This quantum CPU (quCPU?) is a big breakthrough, because quantum computers by definition are difficult to design. They’re based on the concept of superposition — that a quantum bit, or qubit, can exist in two different states at once. Put another way, it can be a 0 or a 1 at the same time, and it can therefore perform calculations more quickly than a system based on 0 or 1. But it’s hard to keep the qubits in a state in which this is possible, and interfering with them — i.e., reading their data — can destroy their superposition capabilities. So, a system that integrates random access memory into the qubits is a big step toward a working computer....