*Quantum Circuits* are the most common visualization of [[Quantum Algorithm|quantum algorithms]]. They help scientists to design and understand the inner workings of [[Quantum Computer|quantum computations]]. ![[quantum_circuit.excalidraw.light.svg]] The structure of the circuit is designed in analogy to [[Logic Gate|logic gates]], a common visualization of [[Boolean Logic|Boolean logic]], and [[Electronic Circuit|electronic circuits]]. The horizontal black wires are transporting information from left to right through the circuit. You can think of them like water pipes, just for [[Quantum Information|quantum information]]. The grey boxes alter the information in the wires and can act on one or more wire at the same time. Since [[Quantum Algorithm|quantum algorithms]] are [[Algorithm|algorithms]] at heart, the general structure of a *quantum circuit* is rather similar to any other algorithm: - **Input preparation (blue box)** At the beginning of the circuit, we give an input into the circuit. If we think of a classical sorting algorithm, this would be the listed that we would like to sort. - **Gate Application (green box)** This is the main part of the algorithm. Here, we apply gates (grey boxes) to the quantum information in the wires and alter the [[Quantum State|quantum state]] represented by the circuit. - **Measurement** At the end of the circuit, we [[Measurement|measure]] the quantum information represented by the circuit to output [[Classical Information|classical information]] back to the user. Note that there are also other paradigms of [[Quantum Computer|quantum computing]], e.g. [[Measurement-based Quantum Computing]] uses measurements instead of gates throughout the circuit. Modern quantum devices allow also mid-circuit measurements to speed up state preparation and computations. >[!read]- Further Reading >- [[Quantum Computer]] >- [[Quantum Algorithm]] >[!ref]- References