Quantum Decoherence
The process by which a quantum system loses its quantum properties through interaction with its environment. The primary enemy of quantum computation.
Quantum decoherence is the process by which a quantum system loses its quantum properties, including superposition, entanglement, and phase relationships, as it interacts with its surrounding environment. Every quantum system is susceptible to decoherence; the question is how long it takes.
For a qubit, decoherence means the quantum information is gradually destroyed by thermal noise, electromagnetic interference, vibrations, and other environmental factors. Once decoherence occurs, the qubit is no longer in a useful quantum state.
Coherence time (also called T1 and T2 times) measures how long a qubit maintains its quantum state before decoherence destroys it. Longer coherence times allow more quantum operations before information is lost.
Trapped ion systems (Quantinuum, Broomfield) and neutral atom systems (Atom Computing, Infleqtion, Boulder) generally have longer coherence times than superconducting systems. This is one of the practical advantages of the approaches Colorado's companies have chosen.