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--- quantum-gate [June 13, 2026 at 00:24] – Ivan Janevski
+++ quantum-gate [June 13, 2026 at 03:13] (current) – external edit 127.0.0.1
@@ Line 6: / Line 6: @@
 Classical logic gates like AND and OR are irreversible — given only the output, you cannot recover both inputs. Quantum gates cannot be irreversible in this way because unitary evolution is bijective. The only irreversible step in a quantum computation is **measurement**, which collapses the state vector and cannot be undone.
-Single-qubit gates are $2 \times 2$ unitary matrices. The most general single-qubit gate is the [[u-gate|U gate]] $U(\theta, \phi, \lambda)$, which subsumes all others as special cases. Two-qubit gates are $4 \times 4$ unitary matrices; the [[cnot-gate|CNOT gate]] is the standard entangling two-qubit gate. Together, single-qubit gates and CNOT form a universal gate set: any $n$-qubit unitary can be approximated to arbitrary precision using only these.
+Single-qubit gates are $2 \times 2$ unitary matrices. The most general single-qubit gate is the [[u-gate|U gate]] $U(\theta, \phi, \lambda)$, which subsumes all others as special cases. Two-qubit gates are $4 \times 4$ unitary matrices; the [[cx-gate|CX gate]] is the standard entangling two-qubit gate. Together, single-qubit gates and CX form a universal gate set: any $n$-qubit unitary can be approximated to arbitrary precision using only these.