What is the Toffoli gate?

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What is the Toffoli gate?

The Toffoli gate, also known as the Controlled-Controlled-Not (CCNOT) gate, is a fundamental gate in quantum computing. It is a three-qubit gate that performs a controlled-NOT operation on the target qubit if and only if both control qubits are in the state |1⟩. In other words, the Toffoli gate flips the state of the target qubit if and only if both control qubits are in the state |1⟩, otherwise it leaves the target qubit unchanged. The Toffoli gate is commonly used in quantum algorithms and quantum error correction codes.