Exploring Robust Bound States of Interacting Photons Using a Quantum Processor

Quantum processors reveal that photons’ bound states are strong, even when chaos is present

Researchers used a quantum process to make microwave photons unusually sticky. The researchers coaxed the photons to cluster together into bound states and then discovered that these photons clusters survived a regime in which they were expected dissolve into their usual solitary state. This discovery was made for the first time on a quantum computer, highlighting their growing importance in studying quantum dynamics.

Photons–quantum packets of electromagnetic radiation like light or microwaves–typically don’t interact with one another. For example, two crossed flashlight beams pass through each other without being disturbed. In an array of superconducting quantum bits, microwave photons are able to interact.

Researchers at Google Quantum AI explain how they created this unique situation in \”Formation robust bound states of photons interacting,\” published today by Nature. The researchers studied a ring made up of 24 superconducting quantum bits that could be used to host microwave photons. Photons can travel by hopping from one site to another and interacting nearby qubits when quantum gates are applied to adjacent pairs of qubits.