Quantum Circuits are used to visualize a prescription of quantum gates acting on a quantum state. They describe the changes of the quantum data as it undergoes successive discrete operations.
The data in a Quantum Circuit is usually encoded in a -qubit state (other Quantum Circuit models can use
-level quantum systems instead of these
-level systems) which is set to a known vale, i.e.
. Thus, for every qubit in the circuit a horizontal rail, a wire, is drawn to represent its evolution, time flows from left to right.

Wires in a Quantum Circuit initialized to the -qubit quantum state
.
Additionally, a Quantum Circuit is built from elementary quantum gates (unitary operations) acting on a fixed number of qubits. Since Quantum Circuits are read from left to right, leftmost gates act first.

Single-qubit and Two-qubit quantum gates in a Quantum Circuit.
Then, a description of the Quantum System consists of
- Input: A controlled input
-qubit state.
- Evolution: Prescribed sequence of Unitary Single-qubit and Two-qubit logic quantum gates which give the evolution of the initial quantum state.
- Output: Readout (measurement) of the state of the
qubits.
Go to the Dictionary of Quantum Information and Quantum Computation.
Quantum Circuits where drawn using this LaTeX package.
All text copyright © Marco Vinicio Sebastian Cerezo de la Roca.
The More You Know: Quantum Circuit por Marco Vinicio Sebastian Cerezo de la Roca se distribuye bajo una Licencia Creative Commons Atribución-NoComercial-CompartirIgual 4.0 Internacional.