5. Hardware: Ions & Photonics

Trapped Ions & Photonics

Trapped Ions (IonQ, Quantinuum):

• Tech: Individual atoms levitated by electric fields.
• Pros: Perfect qubits (nature makes them identical). Long coherence (seconds/minutes). High connectivity.
• Cons: Slow gates. Hard to scale trap size.

Photonics (PsiQuantum, Xanadu):

• Tech: Encoding information in particles of light.
• Pros: Works at room temperature (mostly). Integration with fiber optics.
• Cons: Photons don't like to interact (hard to do 2-qubit gates). Loss is a major issue.