What is the depth of a Toffoli gate when decompressed?

[quantumadmin]

The Toffoli gate is a universal reversible logic gate in classical computation, commonly used in quantum computing as well. When referring to the "depth" of a Toffoli gate in a quantum circuit, we are essentially talking about how many gate layers (or time steps) are required to implement the Toffoli gate using a particular set of quantum gates.

The exact depth of a Toffoli gate's decomposition can vary depending on the specific quantum gate set and decomposition method being used. Different gate sets and decomposition techniques can result in different circuit depths. The goal is often to find an efficient decomposition that minimizes the number of gates and the overall circuit depth.

There are various techniques for decomposing a Toffoli gate into a sequence of fundamental gates such as CNOT gates (controlled-X gates) and single-qubit gates. These decompositions can involve different numbers of gates and thus different depths.