IBM has revealed two new quantum computers, Loon and Nighthawk, featuring unprecedented qubit connections that could advance error-free computing. These machines use a modular design to link superconducting qubits in complex ways, potentially boosting computational power. The development aims to overcome key challenges in scaling quantum technology.
IBM's approach to quantum computing emphasizes modularity and innovative connections between superconducting qubits, both within and across units. The company unveiled Loon and Nighthawk, which demonstrate this strategy's viability. Jay Gambetta at IBM noted initial skepticism from researchers, who dismissed the connections as theoretical. "‘You’re in theory land, you cannot realise that.’ And [now] we’re going to show that [to be] wrong," Gambetta said.
Loon features qubits each connected to six others, with links that "break the plane"—allowing vertical movement across chips, a first for superconducting quantum computers. Nighthawk offers four-way qubit connectivity. This enhanced linking could amplify computational power and reduce errors, critical hurdles for current systems.
Preliminary tests on Nighthawk show it handles quantum programs 30 percent more complex than IBM's most widely used machine. Such advances could expand applications, building on prior uses in chemistry. IBM pursues smaller logical qubits for error correction, differing from competitors like Google, which require more qubits. High connectivity, as in Loon, is essential for this method to avoid massive scaling costs.
Stephen Bartlett at the University of Sydney called the connectivity "exciting" and a "significant major step" toward useful algorithms, though more testing is needed. Remaining challenges include improving output readout, where IBM has progressed, and extending qubit coherence time, which new connections can degrade. The team is also developing ways to reset qubits mid-calculation.
By 2026, IBM plans a modular quantum computer for storage and processing, shaped by Loon and Nighthawk evaluations.