=== Kvantebit operationer og kvantekredsløb ===
Kvantecomputeren beregner ved at udføre disse valgte kvanteoperationer på kvantebits. En del af operationsnavnene er også anvendt i kvanteprogrammeringssproget [[OpenQASM]]:<ref name="code2">[https://www.codeproject.com/Articles/1182207/Quantum-Computing-for-Everyone-Part-II-Quantum-Gat 16 Jun 2018, codeproject.com: Quantum Computing for Everyone - Part II: Quantum Gates], [https://web.archive.org/web/20191111074459/https://www.codeproject.com/Articles/1182207/Quantum-Computing-for-Everyone-Part-II-Quantum-Gat backup]</ref><ref name="code3">[https://www.codeproject.com/Articles/1182208/Quantum-Computing-for-Everyone-Part-III-Quantum-Ci 16 Jun 2018, codeproject.com: Quantum Computing for Everyone - Part III: Quantum Circuits and OpenQASM], [https://web.archive.org/web/20191111074648/https://www.codeproject.com/Articles/1182208/Quantum-Computing-for-Everyone-Part-III-Quantum-Ci backup]</ref><ref>[https://arxiv.org/pdf/1707.03429.pdf Open Quantum Assembly Language. Andrew W. Cross, Lev S. Bishop, John A. Smolin, Jay M. Gambetta January 10th, 2017] Citat: "...Our goal in this document is to describe an interface language for the Quantum Experience that enables experiments with small depth quantum circuits...Compilation. This phase takes place on a classical computer in a setting where specific problem parameters are not yet known and no interaction with the quantum computer is required, i.e. it is offline...Circuit generation. This takes place on a classical computer in an environment where specific problem parameters are now known, and some interaction with the quantum computer may occur, i.e. this is an online phase...Execution. This takes place on physical quantum computer controllers in a real-time environment, i.e. the quantum computer is active...Post-processing. This takes place on a classical computer after all real-time processing is complete...The human-readable form of our quantum circuit IR is based on “quantum assembly language” [3, 23–26] or QASM (pronounced kazm). QASM is a simple text language that describes generic quantum circuits...We choose a simple language without higher level programming primitives. We define different gate sets using a subroutine-like mechanism that hierarchically specifies new unitary gates in terms of built-in gates and previously defined gate subroutines. In this way, the built-in basis is used to define hardware-supported operations via standard header files. The subroutine mechanism allows limited code reuse by hierarchically defining more complex operations [7, 26]. We also add instructions that model a quantum-classical interface, specifically measurement, state reset, and the most elemental classical feedback. The remaining sections of this document specify [[OpenQASM|Open QASM]] and provide examples....", [https://web.archive.org/web/20191111125654/https://arxiv.org/pdf/1707.03429.pdf backup]</ref>
* Enkelt kvantebit operationer:
** reset (sæt kvantebit til <math>|0\rangle</math>)
** U(theta,phi,lambda) = u3(theta,phi,lambda) universal rotations-gate. Kan rotere en kvantetilstand til en vilkårlig anden kvantetilstand på [[Bloch sfære]]n.
*** Specialtilfælde rotations-gates:
**** Identity, id = u3(0,0,0)
**** u1(lambda) = u3(0,0,lambda)
**** Clifford gate: Hadamard, H = u3(pi/2,0,pi).
**** Clifford gate: sqrt(Z) phase gate S = u1(pi/2)
**** Clifford gate: konjugeret sqrt(Z) phase gate Sdg = u1(-pi/2)
**** C3 gate: sqrt(S) phase gate T = u1(pi/4)
**** C3 gate: konjugeret sqrt(S) phase gate Tdg = u1(-pi/4)
**** Pauli-X gate, X gate (NOT gate) = u3(pi,0,pi)
**** Pauli-Y gate, Y gate = u3(pi,pi/2,pi/2)
**** Pauli-Z gate, Z gate (phase flip gate) = u1(pi) = u3(0,0,pi)
**** rx(theta) = u3(theta,-pi/2,pi/2).
**** ry(theta) = u3(theta,0,0).
**** rz(phi) = u1(phi).
** ''measure'' (dansk måling) - måler kvantetilstanden på en eller flere kvantebits og output er klassiske bits med værdierne "0" og "1".
* To kvantebit gates:
** Controlled NOT gate, Toffoli gate, CNOT eller endnu kortere CX.
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