As if to underscore how much researchers want to get off the hype train, IBM is expected to announce in 2023 a processor that will buck the trend of putting more quantum bits, or “qubits,” into use. Qubits are the processing units of quantum computers and can be built using a variety of technologies, including superconducting circuits, trapped ions and photons (quantum particles of light).
IBM has long pursued superconducting qubits, and the company has made steady progress over the years in increasing the number of qubits on a chip. In 2021, for example, IBM rolled out a record 127. In November, it unveiled the 433-qubit Osprey processor, and the company aims to release a 1,121-qubit processor called Condor in 2023.
But this year IBM is also expected to unveil its Heron processor, which has just 133 qubits. It might seem like a step backwards, but as the company is eager to point out, Heron’s qubits will be of the highest quality. And, crucially, each chip will be able to connect directly to other Heron processors, heralding a shift from a single quantum computing chip to a “modular” quantum computer built from multiple processors connected together— — a move that is expected to help quantum computers scale significantly.
Heron is a signal of a larger shift in the quantum computing industry. Thanks to some recent breakthroughs, an aggressive roadmap and high levels of funding, we may see a universal quantum computer sooner than many expected a few years ago, some experts say. “Overall, things are definitely moving fast,” said Michelle Mosca, associate director of the Quantum Computing Institute at the University of Waterloo.
Here are a few areas where experts would like to see progress.
Stringing quantum computers together
IBM’s Project Heron is just the first step into the world of modular quantum computing. These chips will be connected to conventional electronics, so they will not be able to maintain the “quantum nature” of information as it is transferred from one processor to another. But the hope is that eventually these chips, linked together with quantum-friendly optical fibers or microwaves, will open the way to distributed, large-scale quantum computers with up to a million connected qubits. This may be the amount needed to run useful error-correcting quantum algorithms. “We need technology that scales both in size and cost, so modularity is key,” said Jerry Chow, director of hardware systems development at IBM Quantum.