BQP can also be viewed as a bounded-error uniform family of quantum circuits.

Define a quantum algorithm to be a family of quantum circuits (specifically, a uniform circuit family).

A quantum circuit consists of simple quantum gates which act on at most a fixed number of qubits, usually 2 or 3.

For quantum circuits a similar composition of qubit gates can be defined.

Theorem: A quantum circuit using only the following elements can be simulated efficiently on a classical computer:

Similar conclusions may hold for quantum circuits and other related systems.

A quantum circuit has been designed which implements the FRFT.

Some basic concepts of Quantum Mechanics and quantum circuits are reviewed.

Any one-way computation can be made into a quantum circuit by using quantum gates to prepare the resource state.

This quantum circuit implements the quantum Fourier transform on the quantum state .