Glossary
Every technical term this platform uses, with what it means and — the part that is harder to find elsewhere — the mistake it prevents. On this subject the intuitive reading is often the wrong one, so each entry says what a reader would otherwise get wrong.
Circuits
- Two-qubit gate
An operation acting on two qubits at once, which is how entanglement is created.
Easy to get wrong: These are the expensive, error-prone operations on real hardware — typically ten times worse than single-qubit gates, so the two-qubit count matters more than the total.
Resources
- T count
How many T gates a circuit needs. The standard measure of a fault-tolerant circuit's cost.
Easy to get wrong: Each T gate consumes a magic state that must be manufactured, and the factories doing that are usually the majority of the machine — often more than 90% of its physical qubits.
Seen in use on /workbench