Hardware & Errors
Rydberg State
A highly excited atomic state used in neutral atom quantum computers to create strong interactions between nearby atoms.
Definition
A Rydberg state is a highly excited state of an atom, where one electron is pushed to a very high energy level, far from the nucleus. Atoms in this state interact much more strongly with each other than atoms in their normal ground state, which neutral atom quantum computers exploit to perform two-qubit operations.
Technical Definition
By temporarily exciting two nearby neutral atoms into Rydberg states, their strong mutual interaction can be used to implement controlled two-qubit gates, after which the atoms return to their normal, weakly-interacting ground states for storage.
Visual Explanation: An Analogy
Think of a Rydberg state like temporarily inflating a balloon to make it touch a neighboring balloon — atoms that normally don't interact much suddenly become big and strongly interacting for the brief moment needed to perform an operation.
Real-World Use Cases
- The core mechanism enabling two-qubit gates in neutral atom quantum computers like Pasqal's systems
- Also used in some quantum simulation experiments studying many-body physics