Cosmic rays are disrupting the fragile quantum bits inside superconducting processors, posing a serious obstacle to building reliable quantum computers. A recent study published in Nature Communications offers some of the most direct evidence yet that energetic particles from space are triggering correlated errors across entire arrays of superconducting qubits, undermining their ability to maintain the coherence necessary for quantum error correction.

Using a 63-qubit processor, researchers from the Beijing Academy of Quantum Information Sciences and collaborating Chinese institutions detected high-energy particle impacts by monitoring charge-parity changes and bit-flip events across multiple qubits. These changes occur when quasiparticles — which are broken pairs of superconducting electrons — tunnel through the quantum circuits, disrupting the delicate quantum states.